Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

81 files changed, 8079 insertions, 0 deletions

diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/configs/.eslintrc.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/configs/.eslintrc.js
new file mode 100644
index 0000000000..76df4134f5
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/configs/.eslintrc.js
@@ -0,0 +1,8 @@
+"use strict";
+
+module.exports = {
+  rules: {
+    // Require object keys to be sorted.
+    "sort-keys": "error",
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/configs/browser-test.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/configs/browser-test.js
new file mode 100644
index 0000000000..28b51f9ed3
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/configs/browser-test.js
@@ -0,0 +1,91 @@
+// Parent config file for all browser-chrome files.
+"use strict";
+
+module.exports = {
+  env: {
+    browser: true,
+    "mozilla/browser-window": true,
+    "mozilla/simpletest": true,
+    // "node": true
+  },
+
+  // All globals made available in the test environment.
+  globals: {
+    // `$` is defined in SimpleTest.js
+    $: false,
+    Assert: false,
+    BrowserTestUtils: false,
+    ContentTask: false,
+    ContentTaskUtils: false,
+    EventUtils: false,
+    IOUtils: false,
+    PathUtils: false,
+    PromiseDebugging: false,
+    SpecialPowers: false,
+    TestUtils: false,
+    addLoadEvent: false,
+    add_setup: false,
+    add_task: false,
+    content: false,
+    executeSoon: false,
+    expectUncaughtException: false,
+    export_assertions: false,
+    extractJarToTmp: false,
+    finish: false,
+    gTestPath: false,
+    getChromeDir: false,
+    getJar: false,
+    getResolvedURI: false,
+    getRootDirectory: false,
+    getTestFilePath: false,
+    ignoreAllUncaughtExceptions: false,
+    info: false,
+    is: false,
+    isnot: false,
+    ok: false,
+    record: false,
+    registerCleanupFunction: false,
+    requestLongerTimeout: false,
+    setExpectedFailuresForSelfTest: false,
+    stringContains: false,
+    stringMatches: false,
+    todo: false,
+    todo_is: false,
+    todo_isnot: false,
+    waitForClipboard: false,
+    waitForExplicitFinish: false,
+    waitForFocus: false,
+  },
+
+  plugins: ["mozilla", "@microsoft/sdl"],
+
+  rules: {
+    // No using of insecure url, so no http urls
+    "@microsoft/sdl/no-insecure-url": [
+      "error",
+      {
+        exceptions: [
+          "^http:\\/\\/mochi\\.test?.*",
+          "^http:\\/\\/localhost?.*",
+          "^http:\\/\\/127\\.0\\.0\\.1?.*",
+          // Exempt xmlns urls
+          "^http:\\/\\/www\\.w3\\.org?.*",
+          "^http:\\/\\/www\\.mozilla\\.org\\/keymaster\\/gatekeeper?.*",
+          // Exempt urls that start with ftp or ws.
+          "^ws:?.*",
+          "^ftp:?.*",
+        ],
+        varExceptions: ["insecure?.*"],
+      },
+    ],
+    "mozilla/import-content-task-globals": "error",
+    "mozilla/import-headjs-globals": "error",
+    "mozilla/mark-test-function-used": "error",
+    "mozilla/no-addtask-setup": "error",
+    "mozilla/no-arbitrary-setTimeout": "error",
+    "mozilla/no-redeclare-with-import-autofix": [
+      "error",
+      { errorForNonImports: false },
+    ],
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/configs/chrome-test.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/configs/chrome-test.js
new file mode 100644
index 0000000000..fa1e8d6190
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/configs/chrome-test.js
@@ -0,0 +1,61 @@
+// Parent config file for all mochitest files.
+"use strict";
+
+module.exports = {
+  env: {
+    browser: true,
+    "mozilla/browser-window": true,
+  },
+
+  // All globals made available in the test environment.
+  globals: {
+    // SpecialPowers is injected into the window object via SimpleTest.js
+    SpecialPowers: false,
+    extractJarToTmp: false,
+    getChromeDir: false,
+    getJar: false,
+    getResolvedURI: false,
+    getRootDirectory: false,
+  },
+
+  overrides: [
+    {
+      env: {
+        // Ideally we wouldn't be using the simpletest env here, but our uses of
+        // js files mean we pick up everything from the global scope, which could
+        // be any one of a number of html files. So we just allow the basics...
+        "mozilla/simpletest": true,
+      },
+      files: ["*.js"],
+    },
+  ],
+
+  plugins: ["mozilla", "@microsoft/sdl"],
+
+  rules: {
+    // No using of insecure url, so no http urls
+    "@microsoft/sdl/no-insecure-url": [
+      "error",
+      {
+        exceptions: [
+          "^http:\\/\\/mochi\\.test?.*",
+          "^http:\\/\\/localhost?.*",
+          "^http:\\/\\/127\\.0\\.0\\.1?.*",
+          // Exempt xmlns urls
+          "^http:\\/\\/www\\.w3\\.org?.*",
+          "^http:\\/\\/www\\.mozilla\\.org\\/keymaster\\/gatekeeper?.*",
+          // Exempt urls that start with ftp or ws.
+          "^ws:?.*",
+          "^ftp:?.*",
+        ],
+        varExceptions: ["insecure?.*"],
+      },
+    ],
+    "mozilla/import-content-task-globals": "error",
+    "mozilla/import-headjs-globals": "error",
+    "mozilla/mark-test-function-used": "error",
+    // We mis-predict globals for HTML test files in directories shared
+    // with browser tests.
+    "mozilla/no-redeclare-with-import-autofix": "off",
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/configs/mochitest-test.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/configs/mochitest-test.js
new file mode 100644
index 0000000000..3f72193d4d
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/configs/mochitest-test.js
@@ -0,0 +1,59 @@
+// Parent config file for all mochitest files.
+"use strict";
+
+module.exports = {
+  env: {
+    browser: true,
+  },
+
+  // All globals made available in the test environment.
+  globals: {
+    // SpecialPowers is injected into the window object via SimpleTest.js
+    SpecialPowers: false,
+  },
+
+  overrides: [
+    {
+      env: {
+        // Ideally we wouldn't be using the simpletest env here, but our uses of
+        // js files mean we pick up everything from the global scope, which could
+        // be any one of a number of html files. So we just allow the basics...
+        "mozilla/simpletest": true,
+      },
+      files: ["*.js"],
+    },
+  ],
+  plugins: ["mozilla", "@microsoft/sdl"],
+
+  rules: {
+    // No using of insecure url, so no http urls
+    "@microsoft/sdl/no-insecure-url": [
+      "error",
+      {
+        exceptions: [
+          "^http:\\/\\/mochi\\.test?.*",
+          "^http:\\/\\/mochi\\.xorigin-test?.*",
+          "^http:\\/\\/localhost?.*",
+          "^http:\\/\\/127\\.0\\.0\\.1?.*",
+          // Exempt xmlns urls
+          "^http:\\/\\/www\\.w3\\.org?.*",
+          "^http:\\/\\/www\\.mozilla\\.org\\/keymaster\\/gatekeeper?.*",
+          // Exempt urls that start with ftp or ws.
+          "^ws:?.*",
+          "^ftp:?.*",
+        ],
+        varExceptions: ["insecure?.*"],
+      },
+    ],
+    "mozilla/import-content-task-globals": "error",
+    "mozilla/import-headjs-globals": "error",
+    "mozilla/mark-test-function-used": "error",
+    // Turn off no-define-cc-etc for mochitests as these don't have Cc etc defined in the
+    // global scope.
+    "mozilla/no-define-cc-etc": "off",
+    // We mis-predict globals for HTML test files in directories shared
+    // with browser tests, so don't try to "fix" imports that are needed.
+    "mozilla/no-redeclare-with-import-autofix": "off",
+    "no-shadow": "error",
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/configs/recommended.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/configs/recommended.js
new file mode 100644
index 0000000000..a7d8c067f0
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/configs/recommended.js
@@ -0,0 +1,356 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * The configuration is based on eslint:recommended config. The details for all
+ * the ESLint rules, and which ones are in the recommended configuration can
+ * be found here:
+ *
+ * https://eslint.org/docs/rules/
+ */
+module.exports = {
+  env: {
+    browser: true,
+    es2021: true,
+    "mozilla/privileged": true,
+    "mozilla/specific": true,
+  },
+
+  // The prettier configuration here comes from eslint-config-prettier and
+  // turns off all of ESLint's rules related to formatting.
+  extends: ["eslint:recommended", "prettier"],
+
+  overrides: [
+    {
+      // System mjs files and jsm files are not loaded in the browser scope,
+      // so we turn that off for those. Though we do have our own special
+      // environment for them.
+      env: {
+        browser: false,
+        "mozilla/jsm": true,
+      },
+      files: ["**/*.sys.mjs", "**/*.jsm", "**/*.jsm.js"],
+      rules: {
+        "mozilla/lazy-getter-object-name": "error",
+        "mozilla/reject-eager-module-in-lazy-getter": "error",
+        "mozilla/reject-global-this": "error",
+        "mozilla/reject-globalThis-modification": "error",
+        // For all system modules, we expect no properties to need importing,
+        // hence reject everything.
+        "mozilla/reject-importGlobalProperties": ["error", "everything"],
+        "mozilla/reject-mixing-eager-and-lazy": "error",
+        "mozilla/reject-top-level-await": "error",
+        // TODO: Bug 1575506 turn `builtinGlobals` on here.
+        // We can enable builtinGlobals for jsms due to their scopes.
+        "no-redeclare": ["error", { builtinGlobals: false }],
+      },
+    },
+    {
+      files: ["**/*.mjs", "**/*.jsm"],
+      rules: {
+        // Modules are far easier to check for no-unused-vars on a global scope,
+        // than our content files. Hence we turn that on here.
+        "no-unused-vars": [
+          "error",
+          {
+            args: "none",
+            vars: "all",
+          },
+        ],
+      },
+    },
+    {
+      files: ["**/*.sys.mjs"],
+      rules: {
+        "mozilla/use-static-import": "error",
+      },
+    },
+    {
+      excludedFiles: ["**/*.sys.mjs"],
+      files: ["**/*.mjs"],
+      rules: {
+        "mozilla/reject-import-system-module-from-non-system": "error",
+        "mozilla/reject-lazy-imports-into-globals": "error",
+        "no-shadow": ["error", { allow: ["event"], builtinGlobals: true }],
+      },
+    },
+    {
+      files: ["**/*.mjs"],
+      rules: {
+        "mozilla/use-static-import": "error",
+        // This rule defaults to not allowing "use strict" in module files since
+        // they are always loaded in strict mode.
+        strict: "error",
+      },
+    },
+    {
+      files: ["**/*.jsm", "**/*.jsm.js"],
+      rules: {
+        "mozilla/mark-exported-symbols-as-used": "error",
+      },
+    },
+    {
+      env: {
+        browser: false,
+        "mozilla/privileged": false,
+        "mozilla/sjs": true,
+      },
+      files: ["**/*.sjs"],
+      rules: {
+        // TODO Bug 1501127: sjs files have their own sandbox, and do not inherit
+        // the Window backstage pass directly. Turn this rule off for sjs files for
+        // now until we develop a solution.
+        "mozilla/reject-importGlobalProperties": "off",
+      },
+    },
+  ],
+
+  parserOptions: {
+    ecmaVersion: 12,
+  },
+
+  // When adding items to this file please check for effects on sub-directories.
+  plugins: ["html", "fetch-options", "no-unsanitized"],
+
+  // When adding items to this file please check for effects on all of toolkit
+  // and browser
+  rules: {
+    // This may conflict with prettier, so we turn it off.
+    "arrow-body-style": "off",
+
+    // Warn about cyclomatic complexity in functions.
+    // XXX Get this down to 20?
+    complexity: ["error", 34],
+
+    // Functions must always return something or nothing
+    "consistent-return": "error",
+
+    // XXX This rule line should be removed to enable it. See bug 1487642.
+    // Require super() calls in constructors
+    "constructor-super": "off",
+
+    // Require braces around blocks that start a new line
+    curly: ["error", "all"],
+
+    // Encourage the use of dot notation whenever possible.
+    "dot-notation": "error",
+
+    // XXX This rule should be enabled, see Bug 1557040
+    // No credentials submitted with fetch calls
+    "fetch-options/no-fetch-credentials": "off",
+
+    // XXX This rule line should be removed to enable it. See bug 1487642.
+    // Enforce return statements in getters
+    "getter-return": "off",
+
+    // Don't enforce the maximum depth that blocks can be nested. The complexity
+    // rule is a better rule to check this.
+    "max-depth": "off",
+
+    // Maximum depth callbacks can be nested.
+    "max-nested-callbacks": ["error", 10],
+
+    "mozilla/avoid-removeChild": "error",
+    "mozilla/consistent-if-bracing": "error",
+    "mozilla/import-browser-window-globals": "error",
+    "mozilla/import-globals": "error",
+    "mozilla/no-compare-against-boolean-literals": "error",
+    "mozilla/no-cu-reportError": "error",
+    "mozilla/no-define-cc-etc": "error",
+    "mozilla/no-throw-cr-literal": "error",
+    "mozilla/no-useless-parameters": "error",
+    "mozilla/no-useless-removeEventListener": "error",
+    "mozilla/prefer-boolean-length-check": "error",
+    "mozilla/prefer-formatValues": "error",
+    "mozilla/reject-addtask-only": "error",
+    "mozilla/reject-chromeutils-import-params": "error",
+    "mozilla/reject-importGlobalProperties": ["error", "allownonwebidl"],
+    "mozilla/reject-multiple-getters-calls": "error",
+    "mozilla/reject-scriptableunicodeconverter": "warn",
+    "mozilla/rejects-requires-await": "error",
+    "mozilla/use-cc-etc": "error",
+    "mozilla/use-chromeutils-generateqi": "error",
+    "mozilla/use-chromeutils-import": "error",
+    "mozilla/use-default-preference-values": "error",
+    "mozilla/use-includes-instead-of-indexOf": "error",
+    "mozilla/use-isInstance": "error",
+    "mozilla/use-ownerGlobal": "error",
+    "mozilla/use-returnValue": "error",
+    "mozilla/use-services": "error",
+    "mozilla/valid-lazy": "error",
+    "mozilla/valid-services": "error",
+
+    // Use [] instead of Array()
+    "no-array-constructor": "error",
+
+    // Disallow use of arguments.caller or arguments.callee.
+    "no-caller": "error",
+
+    // XXX Bug 1487642 - decide if we want to enable this or not.
+    // Disallow lexical declarations in case clauses
+    "no-case-declarations": "off",
+
+    // XXX Bug 1487642 - decide if we want to enable this or not.
+    // Disallow the use of console
+    "no-console": "off",
+
+    // Disallows expressions where the operation doesn't affect the value.
+    "no-constant-binary-expression": "error",
+
+    // XXX Bug 1487642 - decide if we want to enable this or not.
+    // Disallow constant expressions in conditions
+    "no-constant-condition": "off",
+
+    // No duplicate keys in object declarations
+    "no-dupe-keys": "error",
+
+    // If an if block ends with a return no need for an else block
+    "no-else-return": "error",
+
+    // No empty statements
+    "no-empty": ["error", { allowEmptyCatch: true }],
+
+    // Disallow eval and setInteral/setTimeout with strings
+    "no-eval": "error",
+
+    // Disallow unnecessary calls to .bind()
+    "no-extra-bind": "error",
+
+    // Disallow fallthrough of case statements
+    "no-fallthrough": [
+      "error",
+      {
+        // The eslint rule doesn't allow for case-insensitive regex option.
+        // The following pattern allows for a dash between "fall through" as
+        // well as alternate spelling of "fall thru". The pattern also allows
+        // for an optional "s" at the end of "fall" ("falls through").
+        commentPattern:
+          "[Ff][Aa][Ll][Ll][Ss]?[\\s-]?([Tt][Hh][Rr][Oo][Uu][Gg][Hh]|[Tt][Hh][Rr][Uu])",
+      },
+    ],
+
+    // Disallow assignments to native objects or read-only global variables
+    "no-global-assign": "error",
+
+    // Disallow eval and setInteral/setTimeout with strings
+    "no-implied-eval": "error",
+
+    // This has been superseded since we're using ES6.
+    // Disallow variable or function declarations in nested blocks
+    "no-inner-declarations": "off",
+
+    // Disallow the use of the __iterator__ property
+    "no-iterator": "error",
+
+    // No labels
+    "no-labels": "error",
+
+    // Disallow unnecessary nested blocks
+    "no-lone-blocks": "error",
+
+    // No single if block inside an else block
+    "no-lonely-if": "error",
+
+    // Disallow the use of number literals that immediately lose precision at runtime when converted to JS Number
+    "no-loss-of-precision": "error",
+
+    // Nested ternary statements are confusing
+    "no-nested-ternary": "error",
+
+    // Use {} instead of new Object()
+    "no-new-object": "error",
+
+    // Disallow use of new wrappers
+    "no-new-wrappers": "error",
+
+    // We don't want this, see bug 1551829
+    "no-prototype-builtins": "off",
+
+    // Disable builtinGlobals for no-redeclare as this conflicts with our
+    // globals declarations especially for browser window.
+    "no-redeclare": ["error", { builtinGlobals: false }],
+
+    // Disallow use of event global.
+    "no-restricted-globals": ["error", "event"],
+
+    // Disallows unnecessary `return await ...`.
+    "no-return-await": "error",
+
+    // No unnecessary comparisons
+    "no-self-compare": "error",
+
+    // No comma sequenced statements
+    "no-sequences": "error",
+
+    // No declaring variables from an outer scope
+    // "no-shadow": "error",
+
+    // No declaring variables that hide things like arguments
+    "no-shadow-restricted-names": "error",
+
+    // Disallow throwing literals (eg. throw "error" instead of
+    // throw new Error("error")).
+    "no-throw-literal": "error",
+
+    // Disallow the use of Boolean literals in conditional expressions.
+    "no-unneeded-ternary": "error",
+
+    // No unsanitized use of innerHTML=, document.write() etc.
+    // cf. https://github.com/mozilla/eslint-plugin-no-unsanitized#rule-details
+    "no-unsanitized/method": "error",
+    "no-unsanitized/property": "error",
+
+    // No declaring variables that are never used
+    "no-unused-vars": [
+      "error",
+      {
+        args: "none",
+        vars: "local",
+      },
+    ],
+
+    // No using variables before defined
+    // "no-use-before-define": ["error", "nofunc"],
+
+    // Disallow unnecessary .call() and .apply()
+    "no-useless-call": "error",
+
+    // Don't concatenate string literals together (unless they span multiple
+    // lines)
+    "no-useless-concat": "error",
+
+    // XXX Bug 1487642 - decide if we want to enable this or not.
+    // Disallow unnecessary escape characters
+    "no-useless-escape": "off",
+
+    // Disallow redundant return statements
+    "no-useless-return": "error",
+
+    // No using with
+    "no-with": "error",
+
+    // Require object-literal shorthand with ES6 method syntax
+    "object-shorthand": ["error", "always", { avoidQuotes: true }],
+
+    // This may conflict with prettier, so turn it off.
+    "prefer-arrow-callback": "off",
+
+    // This generates too many false positives that are not easy to work around,
+    // and false positives seem to be inherent in the rule.
+    "require-atomic-updates": "off",
+
+    // XXX Bug 1487642 - decide if we want to enable this or not.
+    // Require generator functions to contain yield
+    "require-yield": "off",
+  },
+
+  // To avoid bad interactions of the html plugin with the xml preprocessor in
+  // eslint-plugin-mozilla, we turn off processing of the html plugin for .xml
+  // files.
+  settings: {
+    "html/xml-extensions": [".xhtml"],
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/configs/require-jsdoc.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/configs/require-jsdoc.js
new file mode 100644
index 0000000000..0a037ab159
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/configs/require-jsdoc.js
@@ -0,0 +1,32 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+module.exports = {
+  plugins: ["jsdoc"],
+
+  rules: {
+    "jsdoc/require-jsdoc": [
+      "error",
+      {
+        require: {
+          ClassDeclaration: true,
+          FunctionDeclaration: false,
+        },
+      },
+    ],
+    "jsdoc/require-param": "error",
+    "jsdoc/require-param-description": "error",
+    "jsdoc/require-param-name": "error",
+    "jsdoc/require-property": "error",
+    "jsdoc/require-property-description": "error",
+    "jsdoc/require-property-name": "error",
+    "jsdoc/require-property-type": "error",
+    "jsdoc/require-returns": "error",
+    "jsdoc/require-returns-check": "error",
+    "jsdoc/require-yields": "error",
+    "jsdoc/require-yields-check": "error",
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/configs/valid-jsdoc.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/configs/valid-jsdoc.js
new file mode 100644
index 0000000000..485dddfbd4
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/configs/valid-jsdoc.js
@@ -0,0 +1,25 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+module.exports = {
+  plugins: ["jsdoc"],
+
+  rules: {
+    "jsdoc/check-access": "error",
+    // Handled by prettier
+    // "jsdoc/check-alignment": "error",
+    "jsdoc/check-param-names": "error",
+    "jsdoc/check-property-names": "error",
+    "jsdoc/check-tag-names": "error",
+    "jsdoc/check-types": "error",
+    "jsdoc/empty-tags": "error",
+    "jsdoc/newline-after-description": "error",
+    "jsdoc/no-multi-asterisks": "error",
+    "jsdoc/require-param-type": "error",
+    "jsdoc/require-returns-type": "error",
+    "jsdoc/valid-types": "error",
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/configs/xpcshell-test.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/configs/xpcshell-test.js
new file mode 100644
index 0000000000..492ecc1ae9
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/configs/xpcshell-test.js
@@ -0,0 +1,50 @@
+// Parent config file for all xpcshell files.
+"use strict";
+
+module.exports = {
+  env: {
+    browser: false,
+    "mozilla/privileged": true,
+    "mozilla/xpcshell": true,
+  },
+
+  overrides: [
+    {
+      // If it is a head file, we turn off global unused variable checks, as it
+      // would require searching the other test files to know if they are used or not.
+      // This would be expensive and slow, and it isn't worth it for head files.
+      // We could get developers to declare as exported, but that doesn't seem worth it.
+      files: "head*.js",
+      rules: {
+        "no-unused-vars": [
+          "error",
+          {
+            args: "none",
+            vars: "local",
+          },
+        ],
+      },
+    },
+    {
+      // No declaring variables that are never used
+      files: "test*.js",
+      rules: {
+        "no-unused-vars": [
+          "error",
+          {
+            args: "none",
+            vars: "all",
+          },
+        ],
+      },
+    },
+  ],
+
+  rules: {
+    "mozilla/import-headjs-globals": "error",
+    "mozilla/mark-test-function-used": "error",
+    "mozilla/no-arbitrary-setTimeout": "error",
+    "mozilla/no-useless-run-test": "error",
+    "no-shadow": "error",
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/environments/browser-window.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/environments/browser-window.js
new file mode 100644
index 0000000000..01f7d512b6
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/environments/browser-window.js
@@ -0,0 +1,119 @@
+/**
+ * @fileoverview Defines the environment when in the browser.xhtml window.
+ *               Imports many globals from various files.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+// -----------------------------------------------------------------------------
+// Rule Definition
+// -----------------------------------------------------------------------------
+
+var fs = require("fs");
+var helpers = require("../helpers");
+var { getScriptGlobals } = require("./utils");
+
+// When updating EXTRA_SCRIPTS or MAPPINGS, be sure to also update the
+// 'support-files' config in `tools/lint/eslint.yml`.
+
+// These are scripts not loaded from browser.xhtml or global-scripts.inc
+// but via other includes.
+const EXTRA_SCRIPTS = [
+  "browser/base/content/nsContextMenu.js",
+  "browser/components/downloads/content/downloads.js",
+  "browser/components/downloads/content/indicator.js",
+  "toolkit/content/customElements.js",
+  "toolkit/content/editMenuOverlay.js",
+];
+
+const extraDefinitions = [
+  // Via Components.utils, defineModuleGetter, defineLazyModuleGetters or
+  // defineLazyScriptGetter (and map to
+  // single) variable.
+  { name: "XPCOMUtils", writable: false },
+  { name: "Task", writable: false },
+  { name: "windowGlobalChild", writable: false },
+  // structuredClone is a new global that would be defined for the `browser`
+  // environment in ESLint, but only Firefox has implemented it currently and so
+  // it isn't in ESLint's globals yet.
+  // https://developer.mozilla.org/docs/Web/API/structuredClone
+  { name: "structuredClone", writable: false },
+];
+
+// Some files in global-scripts.inc need mapping to specific locations.
+const MAPPINGS = {
+  "printUtils.js": "toolkit/components/printing/content/printUtils.js",
+  "panelUI.js": "browser/components/customizableui/content/panelUI.js",
+  "viewSourceUtils.js":
+    "toolkit/components/viewsource/content/viewSourceUtils.js",
+  "browserPlacesViews.js":
+    "browser/components/places/content/browserPlacesViews.js",
+  "places-tree.js": "browser/components/places/content/places-tree.js",
+  "places-menupopup.js":
+    "browser/components/places/content/places-menupopup.js",
+};
+
+const globalScriptsRegExp =
+  /^\s*Services.scriptloader.loadSubScript\(\"(.*?)\", this\);$/;
+
+function getGlobalScriptIncludes(scriptPath) {
+  let fileData;
+  try {
+    fileData = fs.readFileSync(scriptPath, { encoding: "utf8" });
+  } catch (ex) {
+    // The file isn't present, so this isn't an m-c repository.
+    return null;
+  }
+
+  fileData = fileData.split("\n");
+
+  let result = [];
+
+  for (let line of fileData) {
+    let match = line.match(globalScriptsRegExp);
+    if (match) {
+      let sourceFile = match[1]
+        .replace(
+          "chrome://browser/content/search/",
+          "browser/components/search/content/"
+        )
+        .replace(
+          "chrome://browser/content/screenshots/",
+          "browser/components/screenshots/content/"
+        )
+        .replace("chrome://browser/content/", "browser/base/content/")
+        .replace("chrome://global/content/", "toolkit/content/");
+
+      for (let mapping of Object.getOwnPropertyNames(MAPPINGS)) {
+        if (sourceFile.includes(mapping)) {
+          sourceFile = MAPPINGS[mapping];
+        }
+      }
+
+      result.push(sourceFile);
+    }
+  }
+
+  return result;
+}
+
+function getGlobalScripts() {
+  let results = [];
+  for (let scriptPath of helpers.globalScriptPaths) {
+    results = results.concat(getGlobalScriptIncludes(scriptPath));
+  }
+  return results;
+}
+
+module.exports = getScriptGlobals(
+  "browser-window",
+  getGlobalScripts().concat(EXTRA_SCRIPTS),
+  extraDefinitions,
+  {
+    browserjsScripts: getGlobalScripts().concat(EXTRA_SCRIPTS),
+  }
+);
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/environments/chrome-script.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/environments/chrome-script.js
new file mode 100644
index 0000000000..9b0ae54a2e
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/environments/chrome-script.js
@@ -0,0 +1,28 @@
+/**
+ * @fileoverview Defines the environment for SpecialPowers chrome script.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+var { globals } = require("./special-powers-sandbox");
+var util = require("util");
+
+module.exports = {
+  globals: util._extend(
+    {
+      // testing/specialpowers/content/SpecialPowersParent.sys.mjs
+
+      // SPLoadChromeScript block
+      createWindowlessBrowser: false,
+      sendAsyncMessage: false,
+      addMessageListener: false,
+      removeMessageListener: false,
+      actorParent: false,
+    },
+    globals
+  ),
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/environments/chrome-worker.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/environments/chrome-worker.js
new file mode 100644
index 0000000000..db5759b26c
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/environments/chrome-worker.js
@@ -0,0 +1,25 @@
+/**
+ * @fileoverview Defines the environment for chrome workers. This differs
+ *               from normal workers by the fact that `ctypes` can be accessed
+ *               as well.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+var globals = require("globals");
+var util = require("util");
+
+var workerGlobals = util._extend(
+  {
+    ctypes: false,
+  },
+  globals.worker
+);
+
+module.exports = {
+  globals: workerGlobals,
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/environments/frame-script.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/environments/frame-script.js
new file mode 100644
index 0000000000..7ac5c941cf
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/environments/frame-script.js
@@ -0,0 +1,39 @@
+/**
+ * @fileoverview Defines the environment for frame scripts.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+module.exports = {
+  globals: {
+    // dom/chrome-webidl/MessageManager.webidl
+
+    // MessageManagerGlobal
+    dump: false,
+    atob: false,
+    btoa: false,
+
+    // MessageListenerManagerMixin
+    addMessageListener: false,
+    removeMessageListener: false,
+    addWeakMessageListener: false,
+    removeWeakMessageListener: false,
+
+    // MessageSenderMixin
+    sendAsyncMessage: false,
+    processMessageManager: false,
+    remoteType: false,
+
+    // SyncMessageSenderMixin
+    sendSyncMessage: false,
+
+    // ContentFrameMessageManager
+    content: false,
+    docShell: false,
+    tabEventTarget: false,
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/environments/jsm.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/environments/jsm.js
new file mode 100644
index 0000000000..1ff73c04d9
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/environments/jsm.js
@@ -0,0 +1,31 @@
+/**
+ * @fileoverview Defines the environment for jsm files.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+module.exports = {
+  globals: {
+    // These globals are hard-coded and available in .jsm scopes.
+    // https://searchfox.org/mozilla-central/rev/dcb0cfb66e4ed3b9c7fbef1e80572426ff5f3c3a/js/xpconnect/loader/mozJSModuleLoader.cpp#222-223
+    // Although `debug` is allowed for jsm files, this is non-standard and something
+    // we don't want to allow in mjs files. Hence it is not included here.
+    atob: false,
+    btoa: false,
+    dump: false,
+    // The WebAssembly global is available in most (if not all) contexts where
+    // JS can run. It's definitely available in JSMs. So even if this is not
+    // the perfect place to add it, it's not wrong, and we can move it later.
+    WebAssembly: false,
+    // These are hard-coded and available in .jsm scopes.
+    // See BackstagePass::Resolve.
+    fetch: false,
+    crypto: false,
+    indexedDB: false,
+    structuredClone: false,
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/environments/privileged.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/environments/privileged.js
new file mode 100644
index 0000000000..13e81f7cef
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/environments/privileged.js
@@ -0,0 +1,803 @@
+/**
+ * @fileoverview Defines the environment for privileges JS files.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+module.exports = {
+  globals: {
+    // Intl and WebAssembly are available everywhere but are not webIDL definitions.
+    Intl: false,
+    WebAssembly: false,
+    // This list of items is currently obtained manually from the list of
+    // mozilla::dom::constructor::id::ID enumerations in an object directory
+    // generated dom/bindings/RegisterBindings.cpp
+    APZHitResultFlags: false,
+    AbortController: false,
+    AbortSignal: false,
+    AccessibleNode: false,
+    Addon: false,
+    AddonEvent: false,
+    AddonInstall: false,
+    AddonManager: true,
+    AddonManagerPermissions: false,
+    AnalyserNode: false,
+    Animation: false,
+    AnimationEffect: false,
+    AnimationEvent: false,
+    AnimationPlaybackEvent: false,
+    AnimationTimeline: false,
+    AnonymousContent: false,
+    Attr: false,
+    AudioBuffer: false,
+    AudioBufferSourceNode: false,
+    AudioContext: false,
+    AudioDestinationNode: false,
+    AudioListener: false,
+    AudioNode: false,
+    AudioParam: false,
+    AudioParamMap: false,
+    AudioProcessingEvent: false,
+    AudioScheduledSourceNode: false,
+    AudioTrack: false,
+    AudioTrackList: false,
+    AudioWorklet: false,
+    AudioWorkletNode: false,
+    AuthenticatorAssertionResponse: false,
+    AuthenticatorAttestationResponse: false,
+    AuthenticatorResponse: false,
+    BarProp: false,
+    BaseAudioContext: false,
+    BatteryManager: false,
+    BeforeUnloadEvent: false,
+    BiquadFilterNode: false,
+    Blob: false,
+    BlobEvent: false,
+    BoxObject: false,
+    BroadcastChannel: false,
+    BrowsingContext: false,
+    ByteLengthQueuingStrategy: false,
+    CanonicalBrowsingContext: false,
+    CDATASection: false,
+    CSS: false,
+    CSS2Properties: false,
+    CSSAnimation: false,
+    CSSConditionRule: false,
+    CSSCounterStyleRule: false,
+    CSSFontFaceRule: false,
+    CSSFontFeatureValuesRule: false,
+    CSSGroupingRule: false,
+    CSSImportRule: false,
+    CSSKeyframeRule: false,
+    CSSKeyframesRule: false,
+    CSSMediaRule: false,
+    CSSMozDocumentRule: false,
+    CSSNamespaceRule: false,
+    CSSPageRule: false,
+    CSSPseudoElement: false,
+    CSSRule: false,
+    CSSRuleList: false,
+    CSSStyleDeclaration: false,
+    CSSStyleRule: false,
+    CSSStyleSheet: false,
+    CSSSupportsRule: false,
+    CSSTransition: false,
+    Cache: false,
+    CacheStorage: false,
+    CanvasCaptureMediaStream: false,
+    CanvasGradient: false,
+    CanvasPattern: false,
+    CanvasRenderingContext2D: false,
+    CaretPosition: false,
+    CaretStateChangedEvent: false,
+    ChannelMergerNode: false,
+    ChannelSplitterNode: false,
+    ChannelWrapper: false,
+    CharacterData: false,
+    CheckerboardReportService: false,
+    ChildProcessMessageManager: false,
+    ChildSHistory: false,
+    ChromeMessageBroadcaster: false,
+    ChromeMessageSender: false,
+    ChromeNodeList: false,
+    ChromeUtils: false,
+    ChromeWorker: false,
+    Clipboard: false,
+    ClipboardEvent: false,
+    ClonedErrorHolder: false,
+    CloseEvent: false,
+    CommandEvent: false,
+    Comment: false,
+    CompositionEvent: false,
+    ConsoleInstance: false,
+    ConstantSourceNode: false,
+    ContentFrameMessageManager: false,
+    ContentProcessMessageManager: false,
+    ConvolverNode: false,
+    CountQueuingStrategy: false,
+    CreateOfferRequest: false,
+    Credential: false,
+    CredentialsContainer: false,
+    Crypto: false,
+    CryptoKey: false,
+    CustomElementRegistry: false,
+    CustomEvent: false,
+    DOMError: false,
+    DOMException: false,
+    DOMImplementation: false,
+    DOMLocalization: false,
+    DOMMatrix: false,
+    DOMMatrixReadOnly: false,
+    DOMParser: false,
+    DOMPoint: false,
+    DOMPointReadOnly: false,
+    DOMQuad: false,
+    DOMRect: false,
+    DOMRectList: false,
+    DOMRectReadOnly: false,
+    DOMRequest: false,
+    DOMStringList: false,
+    DOMStringMap: false,
+    DOMTokenList: false,
+    DataTransfer: false,
+    DataTransferItem: false,
+    DataTransferItemList: false,
+    DebuggerNotificationObserver: false,
+    DelayNode: false,
+    DeprecationReportBody: false,
+    DeviceLightEvent: false,
+    DeviceMotionEvent: false,
+    DeviceOrientationEvent: false,
+    DeviceProximityEvent: false,
+    Directory: false,
+    Document: false,
+    DocumentFragment: false,
+    DocumentTimeline: false,
+    DocumentType: false,
+    DominatorTree: false,
+    DragEvent: false,
+    DynamicsCompressorNode: false,
+    Element: false,
+    ErrorEvent: false,
+    Event: false,
+    EventSource: false,
+    EventTarget: false,
+    FeaturePolicyViolationReportBody: false,
+    FetchObserver: false,
+    File: false,
+    FileList: false,
+    FileReader: false,
+    FileSystem: false,
+    FileSystemDirectoryEntry: false,
+    FileSystemDirectoryReader: false,
+    FileSystemEntry: false,
+    FileSystemFileEntry: false,
+    Flex: false,
+    FlexItemValues: false,
+    FlexLineValues: false,
+    FluentBundle: false,
+    FluentResource: false,
+    FocusEvent: false,
+    FontFace: false,
+    FontFaceSet: false,
+    FontFaceSetLoadEvent: false,
+    FormData: false,
+    FrameCrashedEvent: false,
+    FrameLoader: false,
+    GainNode: false,
+    Gamepad: false,
+    GamepadAxisMoveEvent: false,
+    GamepadButton: false,
+    GamepadButtonEvent: false,
+    GamepadEvent: false,
+    GamepadHapticActuator: false,
+    GamepadPose: false,
+    GamepadServiceTest: false,
+    Glean: false,
+    GleanPings: false,
+    Grid: false,
+    GridArea: false,
+    GridDimension: false,
+    GridLine: false,
+    GridLines: false,
+    GridTrack: false,
+    GridTracks: false,
+    HTMLAllCollection: false,
+    HTMLAnchorElement: false,
+    HTMLAreaElement: false,
+    HTMLAudioElement: false,
+    Audio: false,
+    HTMLBRElement: false,
+    HTMLBaseElement: false,
+    HTMLBodyElement: false,
+    HTMLButtonElement: false,
+    HTMLCanvasElement: false,
+    HTMLCollection: false,
+    HTMLDListElement: false,
+    HTMLDataElement: false,
+    HTMLDataListElement: false,
+    HTMLDetailsElement: false,
+    HTMLDialogElement: false,
+    HTMLDirectoryElement: false,
+    HTMLDivElement: false,
+    HTMLDocument: false,
+    HTMLElement: false,
+    HTMLEmbedElement: false,
+    HTMLFieldSetElement: false,
+    HTMLFontElement: false,
+    HTMLFormControlsCollection: false,
+    HTMLFormElement: false,
+    HTMLFrameElement: false,
+    HTMLFrameSetElement: false,
+    HTMLHRElement: false,
+    HTMLHeadElement: false,
+    HTMLHeadingElement: false,
+    HTMLHtmlElement: false,
+    HTMLIFrameElement: false,
+    HTMLImageElement: false,
+    Image: false,
+    HTMLInputElement: false,
+    HTMLLIElement: false,
+    HTMLLabelElement: false,
+    HTMLLegendElement: false,
+    HTMLLinkElement: false,
+    HTMLMapElement: false,
+    HTMLMarqueeElement: false,
+    HTMLMediaElement: false,
+    HTMLMenuElement: false,
+    HTMLMenuItemElement: false,
+    HTMLMetaElement: false,
+    HTMLMeterElement: false,
+    HTMLModElement: false,
+    HTMLOListElement: false,
+    HTMLObjectElement: false,
+    HTMLOptGroupElement: false,
+    HTMLOptionElement: false,
+    Option: false,
+    HTMLOptionsCollection: false,
+    HTMLOutputElement: false,
+    HTMLParagraphElement: false,
+    HTMLParamElement: false,
+    HTMLPictureElement: false,
+    HTMLPreElement: false,
+    HTMLProgressElement: false,
+    HTMLQuoteElement: false,
+    HTMLScriptElement: false,
+    HTMLSelectElement: false,
+    HTMLSlotElement: false,
+    HTMLSourceElement: false,
+    HTMLSpanElement: false,
+    HTMLStyleElement: false,
+    HTMLTableCaptionElement: false,
+    HTMLTableCellElement: false,
+    HTMLTableColElement: false,
+    HTMLTableElement: false,
+    HTMLTableRowElement: false,
+    HTMLTableSectionElement: false,
+    HTMLTemplateElement: false,
+    HTMLTextAreaElement: false,
+    HTMLTimeElement: false,
+    HTMLTitleElement: false,
+    HTMLTrackElement: false,
+    HTMLUListElement: false,
+    HTMLUnknownElement: false,
+    HTMLVideoElement: false,
+    HashChangeEvent: false,
+    Headers: false,
+    HeapSnapshot: false,
+    History: false,
+    IDBCursor: false,
+    IDBCursorWithValue: false,
+    IDBDatabase: false,
+    IDBFactory: false,
+    IDBFileHandle: false,
+    IDBFileRequest: false,
+    IDBIndex: false,
+    IDBKeyRange: false,
+    IDBLocaleAwareKeyRange: false,
+    IDBMutableFile: false,
+    IDBObjectStore: false,
+    IDBOpenDBRequest: false,
+    IDBRequest: false,
+    IDBTransaction: false,
+    IDBVersionChangeEvent: false,
+    IIRFilterNode: false,
+    IdleDeadline: false,
+    ImageBitmap: false,
+    ImageBitmapRenderingContext: false,
+    ImageCapture: false,
+    ImageCaptureErrorEvent: false,
+    ImageData: false,
+    ImageDocument: false,
+    InputEvent: false,
+    InspectorFontFace: false,
+    InspectorUtils: false,
+    InstallTriggerImpl: false,
+    IntersectionObserver: false,
+    IntersectionObserverEntry: false,
+    IOUtils: false,
+    JSProcessActorChild: false,
+    JSProcessActorParent: false,
+    JSWindowActorChild: false,
+    JSWindowActorParent: false,
+    KeyEvent: false,
+    KeyboardEvent: false,
+    KeyframeEffect: false,
+    L10nFileSource: false,
+    L10nRegistry: false,
+    Localization: false,
+    Location: false,
+    MIDIAccess: false,
+    MIDIConnectionEvent: false,
+    MIDIInput: false,
+    MIDIInputMap: false,
+    MIDIMessageEvent: false,
+    MIDIOutput: false,
+    MIDIOutputMap: false,
+    MIDIPort: false,
+    MatchGlob: false,
+    MatchPattern: false,
+    MatchPatternSet: false,
+    MediaCapabilities: false,
+    MediaCapabilitiesInfo: false,
+    MediaControlService: false,
+    MediaDeviceInfo: false,
+    MediaDevices: false,
+    MediaElementAudioSourceNode: false,
+    MediaEncryptedEvent: false,
+    MediaError: false,
+    MediaKeyError: false,
+    MediaKeyMessageEvent: false,
+    MediaKeySession: false,
+    MediaKeyStatusMap: false,
+    MediaKeySystemAccess: false,
+    MediaKeys: false,
+    MediaList: false,
+    MediaQueryList: false,
+    MediaQueryListEvent: false,
+    MediaRecorder: false,
+    MediaRecorderErrorEvent: false,
+    MediaSource: false,
+    MediaStream: false,
+    MediaStreamAudioDestinationNode: false,
+    MediaStreamAudioSourceNode: false,
+    MediaStreamEvent: false,
+    MediaStreamTrack: false,
+    MediaStreamTrackEvent: false,
+    MerchantValidationEvent: false,
+    MessageBroadcaster: false,
+    MessageChannel: false,
+    MessageEvent: false,
+    MessageListenerManager: false,
+    MessagePort: false,
+    MessageSender: false,
+    MimeType: false,
+    MimeTypeArray: false,
+    MouseEvent: false,
+    MouseScrollEvent: false,
+    MozCanvasPrintState: false,
+    MozDocumentMatcher: false,
+    MozDocumentObserver: false,
+    MozQueryInterface: false,
+    MozSharedMap: false,
+    MozSharedMapChangeEvent: false,
+    MozStorageAsyncStatementParams: false,
+    MozStorageStatementParams: false,
+    MozStorageStatementRow: false,
+    MozWritableSharedMap: false,
+    MutationEvent: false,
+    MutationObserver: false,
+    MutationRecord: false,
+    NamedNodeMap: false,
+    Navigator: false,
+    NetworkInformation: false,
+    Node: false,
+    NodeFilter: false,
+    NodeIterator: false,
+    NodeList: false,
+    Notification: false,
+    NotifyPaintEvent: false,
+    OfflineAudioCompletionEvent: false,
+    OfflineAudioContext: false,
+    OfflineResourceList: false,
+    OffscreenCanvas: false,
+    OscillatorNode: false,
+    PageTransitionEvent: false,
+    PaintRequest: false,
+    PaintRequestList: false,
+    PannerNode: false,
+    ParentProcessMessageManager: false,
+    Path2D: false,
+    PathUtils: false,
+    PaymentAddress: false,
+    PaymentMethodChangeEvent: false,
+    PaymentRequest: false,
+    PaymentRequestUpdateEvent: false,
+    PaymentResponse: false,
+    PeerConnectionImpl: false,
+    PeerConnectionObserver: false,
+    Performance: false,
+    PerformanceEntry: false,
+    PerformanceEntryEvent: false,
+    PerformanceMark: false,
+    PerformanceMeasure: false,
+    PerformanceNavigation: false,
+    PerformanceNavigationTiming: false,
+    PerformanceObserver: false,
+    PerformanceObserverEntryList: false,
+    PerformanceResourceTiming: false,
+    PerformanceServerTiming: false,
+    PerformanceTiming: false,
+    PeriodicWave: false,
+    PermissionStatus: false,
+    Permissions: false,
+    PlacesBookmark: false,
+    PlacesBookmarkAddition: false,
+    PlacesBookmarkGuid: false,
+    PlacesBookmarkKeyword: false,
+    PlacesBookmarkMoved: false,
+    PlacesBookmarkRemoved: false,
+    PlacesBookmarkTags: false,
+    PlacesBookmarkTime: false,
+    PlacesBookmarkTitle: false,
+    PlacesBookmarkUrl: false,
+    PlacesEvent: false,
+    PlacesHistoryCleared: false,
+    PlacesObservers: false,
+    PlacesPurgeCaches: false,
+    PlacesRanking: false,
+    PlacesVisit: false,
+    PlacesVisitRemoved: false,
+    PlacesVisitTitle: false,
+    PlacesWeakCallbackWrapper: false,
+    Plugin: false,
+    PluginArray: false,
+    PluginCrashedEvent: false,
+    PointerEvent: false,
+    PopStateEvent: false,
+    PopupBlockedEvent: false,
+    PrecompiledScript: false,
+    Presentation: false,
+    PresentationAvailability: false,
+    PresentationConnection: false,
+    PresentationConnectionAvailableEvent: false,
+    PresentationConnectionCloseEvent: false,
+    PresentationConnectionList: false,
+    PresentationReceiver: false,
+    PresentationRequest: false,
+    PrioEncoder: false,
+    ProcessMessageManager: false,
+    ProcessingInstruction: false,
+    ProgressEvent: false,
+    PromiseDebugging: false,
+    PromiseRejectionEvent: false,
+    PublicKeyCredential: false,
+    PushManager: false,
+    PushManagerImpl: false,
+    PushSubscription: false,
+    PushSubscriptionOptions: false,
+    RTCCertificate: false,
+    RTCDTMFSender: false,
+    RTCDTMFToneChangeEvent: false,
+    RTCDataChannel: false,
+    RTCDataChannelEvent: false,
+    RTCIceCandidate: false,
+    RTCPeerConnection: false,
+    RTCPeerConnectionIceEvent: false,
+    RTCPeerConnectionStatic: false,
+    RTCRtpReceiver: false,
+    RTCRtpSender: false,
+    RTCRtpTransceiver: false,
+    RTCSessionDescription: false,
+    RTCStatsReport: false,
+    RTCTrackEvent: false,
+    RadioNodeList: false,
+    Range: false,
+    ReadableStreamBYOBReader: false,
+    ReadableStreamBYOBRequest: false,
+    ReadableByteStreamController: false,
+    ReadableStream: false,
+    ReadableStreamDefaultController: false,
+    ReadableStreamDefaultReader: false,
+    Report: false,
+    ReportBody: false,
+    ReportingObserver: false,
+    Request: false,
+    Response: false,
+    SessionStoreUtils: false,
+    SVGAElement: false,
+    SVGAngle: false,
+    SVGAnimateElement: false,
+    SVGAnimateMotionElement: false,
+    SVGAnimateTransformElement: false,
+    SVGAnimatedAngle: false,
+    SVGAnimatedBoolean: false,
+    SVGAnimatedEnumeration: false,
+    SVGAnimatedInteger: false,
+    SVGAnimatedLength: false,
+    SVGAnimatedLengthList: false,
+    SVGAnimatedNumber: false,
+    SVGAnimatedNumberList: false,
+    SVGAnimatedPreserveAspectRatio: false,
+    SVGAnimatedRect: false,
+    SVGAnimatedString: false,
+    SVGAnimatedTransformList: false,
+    SVGAnimationElement: false,
+    SVGCircleElement: false,
+    SVGClipPathElement: false,
+    SVGComponentTransferFunctionElement: false,
+    SVGDefsElement: false,
+    SVGDescElement: false,
+    SVGElement: false,
+    SVGEllipseElement: false,
+    SVGFEBlendElement: false,
+    SVGFEColorMatrixElement: false,
+    SVGFEComponentTransferElement: false,
+    SVGFECompositeElement: false,
+    SVGFEConvolveMatrixElement: false,
+    SVGFEDiffuseLightingElement: false,
+    SVGFEDisplacementMapElement: false,
+    SVGFEDistantLightElement: false,
+    SVGFEDropShadowElement: false,
+    SVGFEFloodElement: false,
+    SVGFEFuncAElement: false,
+    SVGFEFuncBElement: false,
+    SVGFEFuncGElement: false,
+    SVGFEFuncRElement: false,
+    SVGFEGaussianBlurElement: false,
+    SVGFEImageElement: false,
+    SVGFEMergeElement: false,
+    SVGFEMergeNodeElement: false,
+    SVGFEMorphologyElement: false,
+    SVGFEOffsetElement: false,
+    SVGFEPointLightElement: false,
+    SVGFESpecularLightingElement: false,
+    SVGFESpotLightElement: false,
+    SVGFETileElement: false,
+    SVGFETurbulenceElement: false,
+    SVGFilterElement: false,
+    SVGForeignObjectElement: false,
+    SVGGElement: false,
+    SVGGeometryElement: false,
+    SVGGradientElement: false,
+    SVGGraphicsElement: false,
+    SVGImageElement: false,
+    SVGLength: false,
+    SVGLengthList: false,
+    SVGLineElement: false,
+    SVGLinearGradientElement: false,
+    SVGMPathElement: false,
+    SVGMarkerElement: false,
+    SVGMaskElement: false,
+    SVGMatrix: false,
+    SVGMetadataElement: false,
+    SVGNumber: false,
+    SVGNumberList: false,
+    SVGPathElement: false,
+    SVGPathSegList: false,
+    SVGPatternElement: false,
+    SVGPoint: false,
+    SVGPointList: false,
+    SVGPolygonElement: false,
+    SVGPolylineElement: false,
+    SVGPreserveAspectRatio: false,
+    SVGRadialGradientElement: false,
+    SVGRect: false,
+    SVGRectElement: false,
+    SVGSVGElement: false,
+    SVGScriptElement: false,
+    SVGSetElement: false,
+    SVGStopElement: false,
+    SVGStringList: false,
+    SVGStyleElement: false,
+    SVGSwitchElement: false,
+    SVGSymbolElement: false,
+    SVGTSpanElement: false,
+    SVGTextContentElement: false,
+    SVGTextElement: false,
+    SVGTextPathElement: false,
+    SVGTextPositioningElement: false,
+    SVGTitleElement: false,
+    SVGTransform: false,
+    SVGTransformList: false,
+    SVGUnitTypes: false,
+    SVGUseElement: false,
+    SVGViewElement: false,
+    SVGZoomAndPan: false,
+    Screen: false,
+    ScreenLuminance: false,
+    ScreenOrientation: false,
+    ScriptProcessorNode: false,
+    ScrollAreaEvent: false,
+    ScrollViewChangeEvent: false,
+    SecurityPolicyViolationEvent: false,
+    Selection: false,
+    ServiceWorker: false,
+    ServiceWorkerContainer: false,
+    ServiceWorkerRegistration: false,
+    ShadowRoot: false,
+    SharedWorker: false,
+    SimpleGestureEvent: false,
+    SourceBuffer: false,
+    SourceBufferList: false,
+    SpeechGrammar: false,
+    SpeechGrammarList: false,
+    SpeechRecognition: false,
+    SpeechRecognitionAlternative: false,
+    SpeechRecognitionError: false,
+    SpeechRecognitionEvent: false,
+    SpeechRecognitionResult: false,
+    SpeechRecognitionResultList: false,
+    SpeechSynthesis: false,
+    SpeechSynthesisErrorEvent: false,
+    SpeechSynthesisEvent: false,
+    SpeechSynthesisUtterance: false,
+    SpeechSynthesisVoice: false,
+    StereoPannerNode: false,
+    Storage: false,
+    StorageEvent: false,
+    StorageManager: false,
+    StreamFilter: false,
+    StreamFilterDataEvent: false,
+    StructuredCloneHolder: false,
+    StructuredCloneTester: false,
+    StyleSheet: false,
+    StyleSheetApplicableStateChangeEvent: false,
+    StyleSheetList: false,
+    SubtleCrypto: false,
+    SyncMessageSender: false,
+    TCPServerSocket: false,
+    TCPServerSocketEvent: false,
+    TCPSocket: false,
+    TCPSocketErrorEvent: false,
+    TCPSocketEvent: false,
+    TelemetryStopwatch: false,
+    TestingDeprecatedInterface: false,
+    Text: false,
+    TextClause: false,
+    TextDecoder: false,
+    TextEncoder: false,
+    TextMetrics: false,
+    TextTrack: false,
+    TextTrackCue: false,
+    TextTrackCueList: false,
+    TextTrackList: false,
+    TimeEvent: false,
+    TimeRanges: false,
+    Touch: false,
+    TouchEvent: false,
+    TouchList: false,
+    TrackEvent: false,
+    TransceiverImpl: false,
+    TransformStream: false,
+    TransformStreamDefaultController: false,
+    TransitionEvent: false,
+    TreeColumn: false,
+    TreeColumns: false,
+    TreeContentView: false,
+    TreeWalker: false,
+    U2F: false,
+    UDPMessageEvent: false,
+    UDPSocket: false,
+    UIEvent: false,
+    URL: false,
+    URLSearchParams: false,
+    UserInteraction: false,
+    UserProximityEvent: false,
+    VRDisplay: false,
+    VRDisplayCapabilities: false,
+    VRDisplayEvent: false,
+    VREyeParameters: false,
+    VRFieldOfView: false,
+    VRFrameData: false,
+    VRMockController: false,
+    VRMockDisplay: false,
+    VRPose: false,
+    VRServiceTest: false,
+    VRStageParameters: false,
+    VRSubmitFrameResult: false,
+    VTTCue: false,
+    VTTRegion: false,
+    ValidityState: false,
+    VideoPlaybackQuality: false,
+    VideoTrack: false,
+    VideoTrackList: false,
+    VisualViewport: false,
+    WaveShaperNode: false,
+    WebExtensionContentScript: false,
+    WebExtensionPolicy: false,
+    WebGL2RenderingContext: false,
+    WebGLActiveInfo: false,
+    WebGLBuffer: false,
+    WebGLContextEvent: false,
+    WebGLFramebuffer: false,
+    WebGLProgram: false,
+    WebGLQuery: false,
+    WebGLRenderbuffer: false,
+    WebGLRenderingContext: false,
+    WebGLSampler: false,
+    WebGLShader: false,
+    WebGLShaderPrecisionFormat: false,
+    WebGLSync: false,
+    WebGLTexture: false,
+    WebGLTransformFeedback: false,
+    WebGLUniformLocation: false,
+    WebGLVertexArrayObject: false,
+    WebGPU: false,
+    WebGPUAdapter: false,
+    WebGPUAttachmentState: false,
+    WebGPUBindGroup: false,
+    WebGPUBindGroupLayout: false,
+    WebGPUBindingType: false,
+    WebGPUBlendFactor: false,
+    WebGPUBlendOperation: false,
+    WebGPUBlendState: false,
+    WebGPUBuffer: false,
+    WebGPUBufferUsage: false,
+    WebGPUColorWriteBits: false,
+    WebGPUCommandBuffer: false,
+    WebGPUCommandEncoder: false,
+    WebGPUCompareFunction: false,
+    WebGPUComputePipeline: false,
+    WebGPUDepthStencilState: false,
+    WebGPUDevice: false,
+    WebGPUFence: false,
+    WebGPUFilterMode: false,
+    WebGPUIndexFormat: false,
+    WebGPUInputState: false,
+    WebGPUInputStepMode: false,
+    WebGPULoadOp: false,
+    WebGPULogEntry: false,
+    WebGPUPipelineLayout: false,
+    WebGPUPrimitiveTopology: false,
+    WebGPUQueue: false,
+    WebGPURenderPipeline: false,
+    WebGPUSampler: false,
+    WebGPUShaderModule: false,
+    WebGPUShaderStage: false,
+    WebGPUShaderStageBit: false,
+    WebGPUStencilOperation: false,
+    WebGPUStoreOp: false,
+    WebGPUSwapChain: false,
+    WebGPUTexture: false,
+    WebGPUTextureDimension: false,
+    WebGPUTextureFormat: false,
+    WebGPUTextureUsage: false,
+    WebGPUTextureView: false,
+    WebGPUVertexFormat: false,
+    WebKitCSSMatrix: false,
+    WebSocket: false,
+    WebrtcGlobalInformation: false,
+    WheelEvent: false,
+    Window: false,
+    WindowGlobalChild: false,
+    WindowGlobalParent: false,
+    WindowRoot: false,
+    Worker: false,
+    Worklet: false,
+    WritableStream: false,
+    WritableStreamDefaultController: false,
+    WritableStreamDefaultWriter: false,
+    XMLDocument: false,
+    XMLHttpRequest: false,
+    XMLHttpRequestEventTarget: false,
+    XMLHttpRequestUpload: false,
+    XMLSerializer: false,
+    XPathEvaluator: false,
+    XPathExpression: false,
+    XPathResult: false,
+    XSLTProcessor: false,
+    XULCommandEvent: false,
+    XULElement: false,
+    XULFrameElement: false,
+    XULMenuElement: false,
+    XULPopupElement: false,
+    XULScrollElement: false,
+    XULTextElement: false,
+    console: false,
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/environments/process-script.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/environments/process-script.js
new file mode 100644
index 0000000000..f329a6650b
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/environments/process-script.js
@@ -0,0 +1,38 @@
+/**
+ * @fileoverview Defines the environment for process scripts.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+module.exports = {
+  globals: {
+    // dom/chrome-webidl/MessageManager.webidl
+
+    // MessageManagerGlobal
+    dump: false,
+    atob: false,
+    btoa: false,
+
+    // MessageListenerManagerMixin
+    addMessageListener: false,
+    removeMessageListener: false,
+    addWeakMessageListener: false,
+    removeWeakMessageListener: false,
+
+    // MessageSenderMixin
+    sendAsyncMessage: false,
+    processMessageManager: false,
+    remoteType: false,
+
+    // SyncMessageSenderMixin
+    sendSyncMessage: false,
+
+    // ContentProcessMessageManager
+    initialProcessData: false,
+    sharedData: false,
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/environments/remote-page.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/environments/remote-page.js
new file mode 100644
index 0000000000..5b362ea2e0
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/environments/remote-page.js
@@ -0,0 +1,43 @@
+/**
+ * @fileoverview Defines the environment for remote page.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+module.exports = {
+  globals: {
+    atob: false,
+    btoa: false,
+    RPMAddTRRExcludedDomain: false,
+    RPMGetAppBuildID: false,
+    RPMGetInnerMostURI: false,
+    RPMGetIntPref: false,
+    RPMGetStringPref: false,
+    RPMGetBoolPref: false,
+    RPMSetBoolPref: false,
+    RPMGetFormatURLPref: false,
+    RPMIsTRROnlyFailure: false,
+    RPMIsFirefox: false,
+    RPMIsNativeFallbackFailure: false,
+    RPMIsWindowPrivate: false,
+    RPMSendAsyncMessage: false,
+    RPMSendQuery: false,
+    RPMAddMessageListener: false,
+    RPMRecordTelemetryEvent: false,
+    RPMCheckAlternateHostAvailable: false,
+    RPMAddToHistogram: false,
+    RPMRemoveMessageListener: false,
+    RPMGetHttpResponseHeader: false,
+    RPMTryPingSecureWWWLink: false,
+    RPMOpenSecureWWWLink: false,
+    RPMOpenPreferences: false,
+    RPMGetTRRSkipReason: false,
+    RPMGetTRRDomain: false,
+    RPMIsSiteSpecificTRRError: false,
+    RPMSetTRRDisabledLoadFlags: false,
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/environments/simpletest.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/environments/simpletest.js
new file mode 100644
index 0000000000..2f5dd5c33e
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/environments/simpletest.js
@@ -0,0 +1,35 @@
+/**
+ * @fileoverview Defines the environment for scripts that use the SimpleTest
+ *               mochitest harness. Imports the globals from the relevant files.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+// -----------------------------------------------------------------------------
+// Rule Definition
+// -----------------------------------------------------------------------------
+
+var path = require("path");
+var { getScriptGlobals } = require("./utils");
+
+// When updating this list, be sure to also update the 'support-files' config
+// in `tools/lint/eslint.yml`.
+const simpleTestFiles = [
+  "AccessibilityUtils.js",
+  "ExtensionTestUtils.js",
+  "EventUtils.js",
+  "MockObjects.js",
+  "SimpleTest.js",
+  "WindowSnapshot.js",
+  "paint_listener.js",
+];
+const simpleTestPath = "testing/mochitest/tests/SimpleTest";
+
+module.exports = getScriptGlobals(
+  "simpletest",
+  simpleTestFiles.map(file => path.join(simpleTestPath, file))
+);
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/environments/sjs.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/environments/sjs.js
new file mode 100644
index 0000000000..995c3173d2
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/environments/sjs.js
@@ -0,0 +1,30 @@
+/**
+ * @fileoverview Defines the environment for sjs files.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+module.exports = {
+  globals: {
+    // All these variables are hard-coded to be available for sjs scopes only.
+    // https://searchfox.org/mozilla-central/rev/26a1b0fce12e6dd495a954c542bb1e7bd6e0d548/netwerk/test/httpserver/httpd.js#2879
+    atob: false,
+    btoa: false,
+    ChromeUtils: false,
+    dump: false,
+    getState: false,
+    setState: false,
+    getSharedState: false,
+    setSharedState: false,
+    getObjectState: false,
+    setObjectState: false,
+    registerPathHandler: false,
+    Services: false,
+    // importScripts is also available.
+    importScripts: false,
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/environments/special-powers-sandbox.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/environments/special-powers-sandbox.js
new file mode 100644
index 0000000000..5a28c91883
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/environments/special-powers-sandbox.js
@@ -0,0 +1,46 @@
+/**
+ * @fileoverview Defines the environment for SpecialPowers sandbox.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+module.exports = {
+  globals: {
+    // wantComponents defaults to true,
+    Components: false,
+    Ci: false,
+    Cr: false,
+    Cc: false,
+    Cu: false,
+    Services: false,
+
+    // testing/specialpowers/content/SpecialPowersSandbox.sys.mjs
+
+    // SANDBOX_GLOBALS
+    Blob: false,
+    ChromeUtils: false,
+    FileReader: false,
+    TextDecoder: false,
+    TextEncoder: false,
+    URL: false,
+
+    // EXTRA_IMPORTS
+    EventUtils: false,
+
+    // SpecialPowersSandbox constructor
+    assert: false,
+    Assert: false,
+    BrowsingContext: false,
+    InspectorUtils: false,
+    ok: false,
+    is: false,
+    isnot: false,
+    todo: false,
+    todo_is: false,
+    info: false,
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/environments/specific.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/environments/specific.js
new file mode 100644
index 0000000000..23ebcb5bb1
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/environments/specific.js
@@ -0,0 +1,31 @@
+/**
+ * @fileoverview Defines the environment for the Firefox browser. Allows global
+ *               variables which are non-standard and specific to Firefox.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+module.exports = {
+  globals: {
+    Cc: false,
+    ChromeUtils: false,
+    Ci: false,
+    Components: false,
+    Cr: false,
+    Cu: false,
+    Debugger: false,
+    InstallTrigger: false,
+    // https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/InternalError
+    InternalError: true,
+    Services: false,
+    // https://developer.mozilla.org/docs/Web/API/Window/dump
+    dump: true,
+    openDialog: false,
+    // https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/uneval
+    uneval: false,
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/environments/utils.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/environments/utils.js
new file mode 100644
index 0000000000..aeda690ba5
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/environments/utils.js
@@ -0,0 +1,62 @@
+/**
+ * @fileoverview Provides utilities for setting up environments.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+var path = require("path");
+var helpers = require("../helpers");
+var globals = require("../globals");
+
+/**
+ * Obtains the globals for a list of files.
+ *
+ * @param {Array.<String>} files
+ *   The array of files to get globals for. The paths are relative to the topsrcdir.
+ * @returns {Object}
+ *   Returns an object with keys of the global names and values of if they are
+ *   writable or not.
+ */
+function getGlobalsForScripts(environmentName, files, extraDefinitions) {
+  let fileGlobals = extraDefinitions;
+  const root = helpers.rootDir;
+  for (const file of files) {
+    const fileName = path.join(root, file);
+    try {
+      fileGlobals = fileGlobals.concat(globals.getGlobalsForFile(fileName));
+    } catch (e) {
+      console.error(`Could not load globals from file ${fileName}: ${e}`);
+      console.error(
+        `You may need to update the mappings for the ${environmentName} environment`
+      );
+      throw new Error(`Could not load globals from file ${fileName}: ${e}`);
+    }
+  }
+
+  var globalObjects = {};
+  for (let global of fileGlobals) {
+    globalObjects[global.name] = global.writable;
+  }
+  return globalObjects;
+}
+
+module.exports = {
+  getScriptGlobals(
+    environmentName,
+    files,
+    extraDefinitions = [],
+    extraEnv = {}
+  ) {
+    if (helpers.isMozillaCentralBased()) {
+      return {
+        globals: getGlobalsForScripts(environmentName, files, extraDefinitions),
+        ...extraEnv,
+      };
+    }
+    return helpers.getSavedEnvironmentItems(environmentName);
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/environments/xpcshell.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/environments/xpcshell.js
new file mode 100644
index 0000000000..408bc2e277
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/environments/xpcshell.js
@@ -0,0 +1,59 @@
+/**
+ * @fileoverview Defines the environment for xpcshell test files.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+var { getScriptGlobals } = require("./utils");
+
+const extraGlobals = [
+  // Defined in XPCShellImpl.cpp
+  "print",
+  "readline",
+  "load",
+  "quit",
+  "dumpXPC",
+  "dump",
+  "gc",
+  "gczeal",
+  "options",
+  "sendCommand",
+  "atob",
+  "btoa",
+  "setInterruptCallback",
+  "simulateNoScriptActivity",
+  "registerXPCTestComponents",
+
+  // Assert.sys.mjs globals.
+  "setReporter",
+  "report",
+  "ok",
+  "equal",
+  "notEqual",
+  "deepEqual",
+  "notDeepEqual",
+  "strictEqual",
+  "notStrictEqual",
+  "throws",
+  "rejects",
+  "greater",
+  "greaterOrEqual",
+  "less",
+  "lessOrEqual",
+  // TestingFunctions.cpp globals
+  "allocationMarker",
+  "byteSize",
+  "saveStack",
+];
+
+module.exports = getScriptGlobals(
+  "xpcshell",
+  ["testing/xpcshell/head.js"],
+  extraGlobals.map(g => {
+    return { name: g, writable: false };
+  })
+);
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/globals.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/globals.js
new file mode 100644
index 0000000000..aa3d4258ae
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/globals.js
@@ -0,0 +1,665 @@
+/**
+ * @fileoverview functions for scanning an AST for globals including
+ *               traversing referenced scripts.
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+const path = require("path");
+const fs = require("fs");
+const helpers = require("./helpers");
+const htmlparser = require("htmlparser2");
+
+const callExpressionDefinitions = [
+  /^loader\.lazyGetter\((?:globalThis|this), "(\w+)"/,
+  /^loader\.lazyServiceGetter\((?:globalThis|this), "(\w+)"/,
+  /^loader\.lazyRequireGetter\((?:globalThis|this), "(\w+)"/,
+  /^XPCOMUtils\.defineLazyGetter\((?:globalThis|this), "(\w+)"/,
+  /^XPCOMUtils\.defineLazyModuleGetter\((?:globalThis|this), "(\w+)"/,
+  /^ChromeUtils\.defineLazyGetter\((?:globalThis|this), "(\w+)"/,
+  /^ChromeUtils\.defineModuleGetter\((?:globalThis|this), "(\w+)"/,
+  /^XPCOMUtils\.defineLazyPreferenceGetter\((?:globalThis|this), "(\w+)"/,
+  /^XPCOMUtils\.defineLazyProxy\((?:globalThis|this), "(\w+)"/,
+  /^XPCOMUtils\.defineLazyScriptGetter\((?:globalThis|this), "(\w+)"/,
+  /^XPCOMUtils\.defineLazyServiceGetter\((?:globalThis|this), "(\w+)"/,
+  /^XPCOMUtils\.defineConstant\((?:globalThis|this), "(\w+)"/,
+  /^DevToolsUtils\.defineLazyModuleGetter\((?:globalThis|this), "(\w+)"/,
+  /^DevToolsUtils\.defineLazyGetter\((?:globalThis|this), "(\w+)"/,
+  /^Object\.defineProperty\((?:globalThis|this), "(\w+)"/,
+  /^Reflect\.defineProperty\((?:globalThis|this), "(\w+)"/,
+  /^this\.__defineGetter__\("(\w+)"/,
+];
+
+const callExpressionMultiDefinitions = [
+  "XPCOMUtils.defineLazyGlobalGetters(this,",
+  "XPCOMUtils.defineLazyGlobalGetters(globalThis,",
+  "XPCOMUtils.defineLazyModuleGetters(this,",
+  "XPCOMUtils.defineLazyModuleGetters(globalThis,",
+  "XPCOMUtils.defineLazyServiceGetters(this,",
+  "XPCOMUtils.defineLazyServiceGetters(globalThis,",
+  "ChromeUtils.defineESModuleGetters(this,",
+  "ChromeUtils.defineESModuleGetters(globalThis,",
+  "loader.lazyRequireGetter(this,",
+  "loader.lazyRequireGetter(globalThis,",
+];
+
+const subScriptMatches = [
+  /Services\.scriptloader\.loadSubScript\("(.*?)", this\)/,
+];
+
+const workerImportFilenameMatch = /(.*\/)*((.*?)\.jsm?)/;
+
+/**
+ * Parses a list of "name:boolean_value" or/and "name" options divided by comma
+ * or whitespace.
+ *
+ * This function was copied from eslint.js
+ *
+ * @param {string} string The string to parse.
+ * @param {Comment} comment The comment node which has the string.
+ * @returns {Object} Result map object of names and boolean values
+ */
+function parseBooleanConfig(string, comment) {
+  let items = {};
+
+  // Collapse whitespace around : to make parsing easier
+  string = string.replace(/\s*:\s*/g, ":");
+  // Collapse whitespace around ,
+  string = string.replace(/\s*,\s*/g, ",");
+
+  string.split(/\s|,+/).forEach(function (name) {
+    if (!name) {
+      return;
+    }
+
+    let pos = name.indexOf(":");
+    let value;
+    if (pos !== -1) {
+      value = name.substring(pos + 1, name.length);
+      name = name.substring(0, pos);
+    }
+
+    items[name] = {
+      value: value === "true",
+      comment,
+    };
+  });
+
+  return items;
+}
+
+/**
+ * Global discovery can require parsing many files. This map of
+ * {String} => {Object} caches what globals were discovered for a file path.
+ */
+const globalCache = new Map();
+
+/**
+ * Global discovery can occasionally meet circular dependencies due to the way
+ * js files are included via html/xhtml files etc. This set is used to avoid
+ * getting into loops whilst the discovery is in progress.
+ */
+var globalDiscoveryInProgressForFiles = new Set();
+
+/**
+ * When looking for globals in HTML files, it can be common to have more than
+ * one script tag with inline javascript. These will normally be called together,
+ * so we store the globals for just the last HTML file processed.
+ */
+var lastHTMLGlobals = {};
+
+/**
+ * Attempts to convert an CallExpressions that look like module imports
+ * into global variable definitions.
+ *
+ * @param  {Object} node
+ *         The AST node to convert.
+ * @param  {boolean} isGlobal
+ *         True if the current node is in the global scope.
+ *
+ * @return {Array}
+ *         An array of objects that contain details about the globals:
+ *         - {String} name
+ *                    The name of the global.
+ *         - {Boolean} writable
+ *                     If the global is writeable or not.
+ */
+function convertCallExpressionToGlobals(node, isGlobal) {
+  let express = node.expression;
+  if (
+    express.type === "CallExpression" &&
+    express.callee.type === "MemberExpression" &&
+    express.callee.object &&
+    express.callee.object.type === "Identifier" &&
+    express.arguments.length === 1 &&
+    express.arguments[0].type === "ArrayExpression" &&
+    express.callee.property.type === "Identifier" &&
+    express.callee.property.name === "importGlobalProperties"
+  ) {
+    return express.arguments[0].elements.map(literal => {
+      return {
+        explicit: true,
+        name: literal.value,
+        writable: false,
+      };
+    });
+  }
+
+  let source;
+  try {
+    source = helpers.getASTSource(node);
+  } catch (e) {
+    return [];
+  }
+
+  // The definition matches below must be in the global scope for us to define
+  // a global, so bail out early if we're not a global.
+  if (!isGlobal) {
+    return [];
+  }
+
+  for (let reg of subScriptMatches) {
+    let match = source.match(reg);
+    if (match) {
+      return getGlobalsForScript(match[1], "script").map(g => {
+        // We don't want any loadSubScript globals to be explicit, as this
+        // could trigger no-unused-vars when importing multiple variables
+        // from a script and not using all of them.
+        g.explicit = false;
+        return g;
+      });
+    }
+  }
+
+  for (let reg of callExpressionDefinitions) {
+    let match = source.match(reg);
+    if (match) {
+      return [{ name: match[1], writable: true, explicit: true }];
+    }
+  }
+
+  if (
+    callExpressionMultiDefinitions.some(expr => source.startsWith(expr)) &&
+    node.expression.arguments[1]
+  ) {
+    let arg = node.expression.arguments[1];
+    if (arg.type === "ObjectExpression") {
+      return arg.properties
+        .map(p => ({
+          name: p.type === "Property" && p.key.name,
+          writable: true,
+          explicit: true,
+        }))
+        .filter(g => g.name);
+    }
+    if (arg.type === "ArrayExpression") {
+      return arg.elements
+        .map(p => ({
+          name: p.type === "Literal" && p.value,
+          writable: true,
+          explicit: true,
+        }))
+        .filter(g => typeof g.name == "string");
+    }
+  }
+
+  if (
+    node.expression.callee.type == "MemberExpression" &&
+    node.expression.callee.property.type == "Identifier" &&
+    node.expression.callee.property.name == "defineLazyScriptGetter"
+  ) {
+    // The case where we have a single symbol as a string has already been
+    // handled by the regexp, so we have an array of symbols here.
+    return node.expression.arguments[1].elements.map(n => ({
+      name: n.value,
+      writable: true,
+      explicit: true,
+    }));
+  }
+
+  return [];
+}
+
+/**
+ * Attempts to convert an AssignmentExpression into a global variable
+ * definition if it applies to `this` in the global scope.
+ *
+ * @param  {Object} node
+ *         The AST node to convert.
+ * @param  {boolean} isGlobal
+ *         True if the current node is in the global scope.
+ *
+ * @return {Array}
+ *         An array of objects that contain details about the globals:
+ *         - {String} name
+ *                    The name of the global.
+ *         - {Boolean} writable
+ *                     If the global is writeable or not.
+ */
+function convertThisAssignmentExpressionToGlobals(node, isGlobal) {
+  if (
+    isGlobal &&
+    node.expression.left &&
+    node.expression.left.object &&
+    node.expression.left.object.type === "ThisExpression" &&
+    node.expression.left.property &&
+    node.expression.left.property.type === "Identifier"
+  ) {
+    return [{ name: node.expression.left.property.name, writable: true }];
+  }
+  return [];
+}
+
+/**
+ * Attempts to convert an ExpressionStatement to likely global variable
+ * definitions.
+ *
+ * @param  {Object} node
+ *         The AST node to convert.
+ * @param  {boolean} isGlobal
+ *         True if the current node is in the global scope.
+ *
+ * @return {Array}
+ *         An array of objects that contain details about the globals:
+ *         - {String} name
+ *                    The name of the global.
+ *         - {Boolean} writable
+ *                     If the global is writeable or not.
+ */
+function convertWorkerExpressionToGlobals(node, isGlobal, dirname) {
+  let results = [];
+  let expr = node.expression;
+
+  if (
+    node.expression.type === "CallExpression" &&
+    expr.callee &&
+    expr.callee.type === "Identifier" &&
+    expr.callee.name === "importScripts"
+  ) {
+    for (var arg of expr.arguments) {
+      var match = arg.value && arg.value.match(workerImportFilenameMatch);
+      if (match) {
+        if (!match[1]) {
+          let filePath = path.resolve(dirname, match[2]);
+          if (fs.existsSync(filePath)) {
+            let additionalGlobals = module.exports.getGlobalsForFile(filePath);
+            results = results.concat(additionalGlobals);
+          }
+        }
+        // Import with relative/absolute path should explicitly use
+        // `import-globals-from` comment.
+      }
+    }
+  }
+
+  return results;
+}
+
+/**
+ * Attempts to load the globals for a given script.
+ *
+ * @param {string} src
+ *   The source path or url of the script to look for.
+ * @param {string} type
+ *   The type of the current file (script/module).
+ * @param {string} [dir]
+ *   The directory of the current file.
+ * @returns {object[]}
+ *   An array of objects with details of the globals in them.
+ */
+function getGlobalsForScript(src, type, dir) {
+  let scriptName;
+  if (src.includes("http:")) {
+    // We don't handle this currently as the paths are complex to match.
+  } else if (src.startsWith("chrome://mochikit/content/")) {
+    // Various ways referencing test files.
+    src = src.replace("chrome://mochikit/content/", "/");
+    scriptName = path.join(helpers.rootDir, "testing", "mochitest", src);
+  } else if (src.startsWith("chrome://mochitests/content/browser")) {
+    src = src.replace("chrome://mochitests/content/browser", "");
+    scriptName = path.join(helpers.rootDir, src);
+  } else if (src.includes("SimpleTest")) {
+    // This is another way of referencing test files...
+    scriptName = path.join(helpers.rootDir, "testing", "mochitest", src);
+  } else if (src.startsWith("/tests/")) {
+    scriptName = path.join(helpers.rootDir, src.substring(7));
+  } else if (dir) {
+    // Fallback to hoping this is a relative path.
+    scriptName = path.join(dir, src);
+  }
+  if (scriptName && fs.existsSync(scriptName)) {
+    return module.exports.getGlobalsForFile(scriptName, {
+      ecmaVersion: helpers.getECMAVersion(),
+      sourceType: type,
+    });
+  }
+  return [];
+}
+
+/**
+ * An object that returns found globals for given AST node types. Each prototype
+ * property should be named for a node type and accepts a node parameter and a
+ * parents parameter which is a list of the parent nodes of the current node.
+ * Each returns an array of globals found.
+ *
+ * @param  {String} filePath
+ *         The absolute path of the file being parsed.
+ */
+function GlobalsForNode(filePath, context) {
+  this.path = filePath;
+  this.context = context;
+
+  if (this.path) {
+    this.dirname = path.dirname(this.path);
+  } else {
+    this.dirname = null;
+  }
+}
+
+GlobalsForNode.prototype = {
+  Program(node) {
+    let globals = [];
+    for (let comment of node.comments) {
+      if (comment.type !== "Block") {
+        continue;
+      }
+      let value = comment.value.trim();
+      value = value.replace(/\n/g, "");
+
+      // We have to discover any globals that ESLint would have defined through
+      // comment directives.
+      let match = /^globals?\s+(.+)/.exec(value);
+      if (match) {
+        let values = parseBooleanConfig(match[1].trim(), node);
+        for (let name of Object.keys(values)) {
+          globals.push({
+            name,
+            writable: values[name].value,
+          });
+        }
+        // We matched globals, so we won't match import-globals-from.
+        continue;
+      }
+
+      match = /^import-globals-from\s+(.+)$/.exec(value);
+      if (!match) {
+        continue;
+      }
+
+      if (!this.dirname) {
+        // If this is testing context without path, ignore import.
+        return globals;
+      }
+
+      let filePath = match[1].trim();
+
+      if (filePath.endsWith(".mjs")) {
+        if (this.context) {
+          this.context.report(
+            comment,
+            "import-globals-from does not support module files - use a direct import instead"
+          );
+        } else {
+          // Fall back to throwing an error, as we do not have a context in all situations,
+          // e.g. when loading the environment.
+          throw new Error(
+            "import-globals-from does not support module files - use a direct import instead"
+          );
+        }
+        continue;
+      }
+
+      if (!path.isAbsolute(filePath)) {
+        filePath = path.resolve(this.dirname, filePath);
+      } else {
+        filePath = path.join(helpers.rootDir, filePath);
+      }
+      globals = globals.concat(module.exports.getGlobalsForFile(filePath));
+    }
+
+    return globals;
+  },
+
+  ExpressionStatement(node, parents, globalScope) {
+    let isGlobal = helpers.getIsGlobalThis(parents);
+    let globals = [];
+
+    // Note: We check the expression types here and only call the necessary
+    // functions to aid performance.
+    if (node.expression.type === "AssignmentExpression") {
+      globals = convertThisAssignmentExpressionToGlobals(node, isGlobal);
+    } else if (node.expression.type === "CallExpression") {
+      globals = convertCallExpressionToGlobals(node, isGlobal);
+    }
+
+    // Here we assume that if importScripts is set in the global scope, then
+    // this is a worker. It would be nice if eslint gave us a way of getting
+    // the environment directly.
+    //
+    // If this is testing context without path, ignore import.
+    if (globalScope && globalScope.set.get("importScripts") && this.dirname) {
+      let workerDetails = convertWorkerExpressionToGlobals(
+        node,
+        isGlobal,
+        this.dirname
+      );
+      globals = globals.concat(workerDetails);
+    }
+
+    return globals;
+  },
+};
+
+module.exports = {
+  /**
+   * Returns all globals for a given file. Recursively searches through
+   * import-globals-from directives and also includes globals defined by
+   * standard eslint directives.
+   *
+   * @param  {String} filePath
+   *         The absolute path of the file to be parsed.
+   * @param  {Object} astOptions
+   *         Extra options to pass to the parser.
+   * @return {Array}
+   *         An array of objects that contain details about the globals:
+   *         - {String} name
+   *                    The name of the global.
+   *         - {Boolean} writable
+   *                     If the global is writeable or not.
+   */
+  getGlobalsForFile(filePath, astOptions = {}) {
+    if (globalCache.has(filePath)) {
+      return globalCache.get(filePath);
+    }
+
+    if (globalDiscoveryInProgressForFiles.has(filePath)) {
+      // We're already processing this file, so return an empty set for now -
+      // the initial processing will pick up on the globals for this file.
+      return [];
+    }
+    globalDiscoveryInProgressForFiles.add(filePath);
+
+    let content = fs.readFileSync(filePath, "utf8");
+
+    // Parse the content into an AST
+    let { ast, scopeManager, visitorKeys } = helpers.parseCode(
+      content,
+      astOptions
+    );
+
+    // Discover global declarations
+    let globalScope = scopeManager.acquire(ast);
+
+    let globals = Object.keys(globalScope.variables).map(v => ({
+      name: globalScope.variables[v].name,
+      writable: true,
+    }));
+
+    // Walk over the AST to find any of our custom globals
+    let handler = new GlobalsForNode(filePath);
+
+    helpers.walkAST(ast, visitorKeys, (type, node, parents) => {
+      if (type in handler) {
+        let newGlobals = handler[type](node, parents, globalScope);
+        globals.push.apply(globals, newGlobals);
+      }
+    });
+
+    globalCache.set(filePath, globals);
+
+    globalDiscoveryInProgressForFiles.delete(filePath);
+    return globals;
+  },
+
+  /**
+   * Returns all globals for a code.
+   * This is only for testing.
+   *
+   * @param  {String} code
+   *         The JS code
+   * @param  {Object} astOptions
+   *         Extra options to pass to the parser.
+   * @return {Array}
+   *         An array of objects that contain details about the globals:
+   *         - {String} name
+   *                    The name of the global.
+   *         - {Boolean} writable
+   *                     If the global is writeable or not.
+   */
+  getGlobalsForCode(code, astOptions = {}) {
+    // Parse the content into an AST
+    let { ast, scopeManager, visitorKeys } = helpers.parseCode(
+      code,
+      astOptions,
+      { useBabel: false }
+    );
+
+    // Discover global declarations
+    let globalScope = scopeManager.acquire(ast);
+
+    let globals = Object.keys(globalScope.variables).map(v => ({
+      name: globalScope.variables[v].name,
+      writable: true,
+    }));
+
+    // Walk over the AST to find any of our custom globals
+    let handler = new GlobalsForNode(null);
+
+    helpers.walkAST(ast, visitorKeys, (type, node, parents) => {
+      if (type in handler) {
+        let newGlobals = handler[type](node, parents, globalScope);
+        globals.push.apply(globals, newGlobals);
+      }
+    });
+
+    return globals;
+  },
+
+  /**
+   * Returns all the globals for an html file that are defined by imported
+   * scripts (i.e. <script src="foo.js">).
+   *
+   * This function will cache results for one html file only - we expect
+   * this to be called sequentially for each chunk of a HTML file, rather
+   * than chucks of different files in random order.
+   *
+   * @param  {String} filePath
+   *         The absolute path of the file to be parsed.
+   * @return {Array}
+   *         An array of objects that contain details about the globals:
+   *         - {String} name
+   *                    The name of the global.
+   *         - {Boolean} writable
+   *                     If the global is writeable or not.
+   */
+  getImportedGlobalsForHTMLFile(filePath) {
+    if (lastHTMLGlobals.filename === filePath) {
+      return lastHTMLGlobals.globals;
+    }
+
+    let dir = path.dirname(filePath);
+    let globals = [];
+
+    let content = fs.readFileSync(filePath, "utf8");
+    let scriptSrcs = [];
+
+    // We use htmlparser as this ensures we find the script tags correctly.
+    let parser = new htmlparser.Parser(
+      {
+        onopentag(name, attribs) {
+          if (name === "script" && "src" in attribs) {
+            scriptSrcs.push({
+              src: attribs.src,
+              type:
+                "type" in attribs && attribs.type == "module"
+                  ? "module"
+                  : "script",
+            });
+          }
+        },
+      },
+      {
+        xmlMode: filePath.endsWith("xhtml"),
+      }
+    );
+
+    parser.parseComplete(content);
+
+    for (let script of scriptSrcs) {
+      // Ensure that the script src isn't just "".
+      if (!script.src) {
+        continue;
+      }
+      globals.push(...getGlobalsForScript(script.src, script.type, dir));
+    }
+
+    lastHTMLGlobals.filePath = filePath;
+    return (lastHTMLGlobals.globals = globals);
+  },
+
+  /**
+   * Intended to be used as-is for an ESLint rule that parses for globals in
+   * the current file and recurses through import-globals-from directives.
+   *
+   * @param  {Object} context
+   *         The ESLint parsing context.
+   */
+  getESLintGlobalParser(context) {
+    let globalScope;
+
+    let parser = {
+      Program(node) {
+        globalScope = context.getScope();
+      },
+    };
+    let filename = context.getFilename();
+
+    let extraHTMLGlobals = [];
+    if (filename.endsWith(".html") || filename.endsWith(".xhtml")) {
+      extraHTMLGlobals = module.exports.getImportedGlobalsForHTMLFile(filename);
+    }
+
+    // Install thin wrappers around GlobalsForNode
+    let handler = new GlobalsForNode(helpers.getAbsoluteFilePath(context));
+
+    for (let type of Object.keys(GlobalsForNode.prototype)) {
+      parser[type] = function (node) {
+        if (type === "Program") {
+          globalScope = context.getScope();
+          helpers.addGlobals(extraHTMLGlobals, globalScope);
+        }
+        let globals = handler[type](node, context.getAncestors(), globalScope);
+        helpers.addGlobals(
+          globals,
+          globalScope,
+          node.type !== "Program" && node
+        );
+      };
+    }
+
+    return parser;
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/helpers.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/helpers.js
new file mode 100644
index 0000000000..640d3bf1a0
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/helpers.js
@@ -0,0 +1,805 @@
+/**
+ * @fileoverview A collection of helper functions.
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+"use strict";
+
+const parser = require("@babel/eslint-parser");
+const { analyze } = require("eslint-scope");
+const { KEYS: defaultVisitorKeys } = require("eslint-visitor-keys");
+const estraverse = require("estraverse");
+const path = require("path");
+const fs = require("fs");
+const ini = require("multi-ini");
+const recommendedConfig = require("./configs/recommended");
+
+var gRootDir = null;
+var directoryManifests = new Map();
+
+let xpidlData;
+
+module.exports = {
+  get iniParser() {
+    if (!this._iniParser) {
+      this._iniParser = new ini.Parser();
+    }
+    return this._iniParser;
+  },
+
+  get servicesData() {
+    return require("./services.json");
+  },
+
+  /**
+   * Obtains xpidl data from the object directory specified in the
+   * environment.
+   *
+   * @returns {Map<string, object>}
+   *   A map of interface names to the interface details.
+   */
+  get xpidlData() {
+    let xpidlDir;
+
+    if (process.env.TASK_ID && !process.env.MOZ_XPT_ARTIFACTS_DIR) {
+      throw new Error(
+        "MOZ_XPT_ARTIFACTS_DIR must be set for this rule in automation"
+      );
+    }
+    xpidlDir = process.env.MOZ_XPT_ARTIFACTS_DIR;
+
+    if (!xpidlDir && process.env.MOZ_OBJDIR) {
+      xpidlDir = `${process.env.MOZ_OBJDIR}/dist/xpt_artifacts/`;
+      if (!fs.existsSync(xpidlDir)) {
+        xpidlDir = `${process.env.MOZ_OBJDIR}/config/makefiles/xpidl/`;
+      }
+    }
+    if (!xpidlDir) {
+      throw new Error(
+        "MOZ_OBJDIR must be defined in the environment for this rule, i.e. MOZ_OBJDIR=objdir-ff ./mach ..."
+      );
+    }
+    if (xpidlData) {
+      return xpidlData;
+    }
+    let files = fs.readdirSync(`${xpidlDir}`);
+    // `Makefile` is an expected file in the directory.
+    if (files.length <= 1) {
+      throw new Error("Missing xpidl data files, maybe you need to build?");
+    }
+    xpidlData = new Map();
+    for (let file of files) {
+      if (!file.endsWith(".xpt")) {
+        continue;
+      }
+      let data = JSON.parse(fs.readFileSync(path.join(`${xpidlDir}`, file)));
+      for (let details of data) {
+        xpidlData.set(details.name, details);
+      }
+    }
+    return xpidlData;
+  },
+
+  /**
+   * Gets the abstract syntax tree (AST) of the JavaScript source code contained
+   * in sourceText. This matches the results for an eslint parser, see
+   * https://eslint.org/docs/developer-guide/working-with-custom-parsers.
+   *
+   * @param  {String} sourceText
+   *         Text containing valid JavaScript.
+   * @param  {Object} astOptions
+   *         Extra configuration to pass to the espree parser, these will override
+   *         the configuration from getPermissiveConfig().
+   * @param  {Object} configOptions
+   *         Extra options for getPermissiveConfig().
+   *
+   * @return {Object}
+   *         Returns an object containing `ast`, `scopeManager` and
+   *         `visitorKeys`
+   */
+  parseCode(sourceText, astOptions = {}, configOptions = {}) {
+    // Use a permissive config file to allow parsing of anything that Espree
+    // can parse.
+    let config = { ...this.getPermissiveConfig(configOptions), ...astOptions };
+
+    let parseResult =
+      "parseForESLint" in parser
+        ? parser.parseForESLint(sourceText, config)
+        : { ast: parser.parse(sourceText, config) };
+
+    let visitorKeys = parseResult.visitorKeys || defaultVisitorKeys;
+    visitorKeys.ExperimentalRestProperty = visitorKeys.RestElement;
+    visitorKeys.ExperimentalSpreadProperty = visitorKeys.SpreadElement;
+
+    return {
+      ast: parseResult.ast,
+      scopeManager: parseResult.scopeManager || analyze(parseResult.ast),
+      visitorKeys,
+    };
+  },
+
+  /**
+   * A simplistic conversion of some AST nodes to a standard string form.
+   *
+   * @param  {Object} node
+   *         The AST node to convert.
+   *
+   * @return {String}
+   *         The JS source for the node.
+   */
+  getASTSource(node, context) {
+    switch (node.type) {
+      case "MemberExpression":
+        if (node.computed) {
+          let filename = context && context.getFilename();
+          throw new Error(
+            `getASTSource unsupported computed MemberExpression in ${filename}`
+          );
+        }
+        return (
+          this.getASTSource(node.object) +
+          "." +
+          this.getASTSource(node.property)
+        );
+      case "ThisExpression":
+        return "this";
+      case "Identifier":
+        return node.name;
+      case "Literal":
+        return JSON.stringify(node.value);
+      case "CallExpression":
+        var args = node.arguments.map(a => this.getASTSource(a)).join(", ");
+        return this.getASTSource(node.callee) + "(" + args + ")";
+      case "ObjectExpression":
+        return "{}";
+      case "ExpressionStatement":
+        return this.getASTSource(node.expression) + ";";
+      case "FunctionExpression":
+        return "function() {}";
+      case "ArrayExpression":
+        return "[" + node.elements.map(this.getASTSource, this).join(",") + "]";
+      case "ArrowFunctionExpression":
+        return "() => {}";
+      case "AssignmentExpression":
+        return (
+          this.getASTSource(node.left) + " = " + this.getASTSource(node.right)
+        );
+      case "BinaryExpression":
+        return (
+          this.getASTSource(node.left) +
+          " " +
+          node.operator +
+          " " +
+          this.getASTSource(node.right)
+        );
+      case "UnaryExpression":
+        return node.operator + " " + this.getASTSource(node.argument);
+      default:
+        throw new Error("getASTSource unsupported node type: " + node.type);
+    }
+  },
+
+  /**
+   * This walks an AST in a manner similar to ESLint passing node events to the
+   * listener. The listener is expected to be a simple function
+   * which accepts node type, node and parents arguments.
+   *
+   * @param  {Object} ast
+   *         The AST to walk.
+   * @param  {Array} visitorKeys
+   *         The visitor keys to use for the AST.
+   * @param  {Function} listener
+   *         A callback function to call for the nodes. Passed three arguments,
+   *         event type, node and an array of parent nodes for the current node.
+   */
+  walkAST(ast, visitorKeys, listener) {
+    let parents = [];
+
+    estraverse.traverse(ast, {
+      enter(node, parent) {
+        listener(node.type, node, parents);
+
+        parents.push(node);
+      },
+
+      leave(node, parent) {
+        if (!parents.length) {
+          throw new Error("Left more nodes than entered.");
+        }
+        parents.pop();
+      },
+
+      keys: visitorKeys,
+    });
+    if (parents.length) {
+      throw new Error("Entered more nodes than left.");
+    }
+  },
+
+  /**
+   * Add a variable to the current scope.
+   * HACK: This relies on eslint internals so it could break at any time.
+   *
+   * @param {String} name
+   *        The variable name to add to the scope.
+   * @param {ASTScope} scope
+   *        The scope to add to.
+   * @param {boolean} writable
+   *        Whether the global can be overwritten.
+   * @param {Object} [node]
+   *        The AST node that defined the globals.
+   */
+  addVarToScope(name, scope, writable, node) {
+    scope.__defineGeneric(name, scope.set, scope.variables, null, null);
+
+    let variable = scope.set.get(name);
+    variable.eslintExplicitGlobal = false;
+    variable.writeable = writable;
+    if (node) {
+      variable.defs.push({
+        type: "Variable",
+        node,
+        name: { name, parent: node.parent },
+      });
+      variable.identifiers.push(node);
+    }
+
+    // Walk to the global scope which holds all undeclared variables.
+    while (scope.type != "global") {
+      scope = scope.upper;
+    }
+
+    // "through" contains all references with no found definition.
+    scope.through = scope.through.filter(function (reference) {
+      if (reference.identifier.name != name) {
+        return true;
+      }
+
+      // Links the variable and the reference.
+      // And this reference is removed from `Scope#through`.
+      reference.resolved = variable;
+      variable.references.push(reference);
+      return false;
+    });
+  },
+
+  /**
+   * Adds a set of globals to a scope.
+   *
+   * @param {Array} globalVars
+   *        An array of global variable names.
+   * @param {ASTScope} scope
+   *        The scope.
+   * @param {Object} [node]
+   *        The AST node that defined the globals.
+   */
+  addGlobals(globalVars, scope, node) {
+    globalVars.forEach(v =>
+      this.addVarToScope(v.name, scope, v.writable, v.explicit && node)
+    );
+  },
+
+  /**
+   * To allow espree to parse almost any JavaScript we need as many features as
+   * possible turned on. This method returns that config.
+   *
+   * @param {Object} options
+   *        {
+   *          useBabel: {boolean} whether to set babelOptions.
+   *        }
+   * @return {Object}
+   *         Espree compatible permissive config.
+   */
+  getPermissiveConfig({ useBabel = true } = {}) {
+    const config = {
+      range: true,
+      requireConfigFile: false,
+      babelOptions: {
+        // configFile: path.join(gRootDir, ".babel-eslint.rc.js"),
+        // parserOpts: {
+        //   plugins: [
+        //     "@babel/plugin-proposal-class-static-block",
+        //     "@babel/plugin-syntax-class-properties",
+        //     "@babel/plugin-syntax-jsx",
+        //   ],
+        // },
+      },
+      loc: true,
+      comment: true,
+      attachComment: true,
+      ecmaVersion: this.getECMAVersion(),
+      sourceType: "script",
+    };
+
+    if (useBabel && this.isMozillaCentralBased()) {
+      config.babelOptions.configFile = path.join(
+        gRootDir,
+        ".babel-eslint.rc.js"
+      );
+    }
+    return config;
+  },
+
+  /**
+   * Returns the ECMA version of the recommended config.
+   *
+   * @return {Number} The ECMA version of the recommended config.
+   */
+  getECMAVersion() {
+    return recommendedConfig.parserOptions.ecmaVersion;
+  },
+
+  /**
+   * Check whether it's inside top-level script.
+   *
+   * @param {Array} ancestors
+   *        The parents of the current node.
+   *
+   * @return {Boolean}
+   *         True or false
+   */
+  getIsTopLevelScript(ancestors) {
+    for (let parent of ancestors) {
+      switch (parent.type) {
+        case "ArrowFunctionExpression":
+        case "FunctionDeclaration":
+        case "FunctionExpression":
+        case "PropertyDefinition":
+        case "StaticBlock":
+          return false;
+      }
+    }
+    return true;
+  },
+
+  isTopLevel(ancestors) {
+    for (let parent of ancestors) {
+      switch (parent.type) {
+        case "ArrowFunctionExpression":
+        case "FunctionDeclaration":
+        case "FunctionExpression":
+        case "PropertyDefinition":
+        case "StaticBlock":
+        case "BlockStatement":
+          return false;
+      }
+    }
+    return true;
+  },
+
+  /**
+   * Check whether `this` expression points the global this.
+   *
+   * @param {Array} ancestors
+   *        The parents of the current node.
+   *
+   * @return {Boolean}
+   *         True or false
+   */
+  getIsGlobalThis(ancestors) {
+    for (let parent of ancestors) {
+      switch (parent.type) {
+        case "FunctionDeclaration":
+        case "FunctionExpression":
+        case "PropertyDefinition":
+        case "StaticBlock":
+          return false;
+      }
+    }
+    return true;
+  },
+
+  /**
+   * Check whether the node is evaluated at top-level script unconditionally.
+   *
+   * @param {Array} ancestors
+   *        The parents of the current node.
+   *
+   * @return {Boolean}
+   *         True or false
+   */
+  getIsTopLevelAndUnconditionallyExecuted(ancestors) {
+    for (let parent of ancestors) {
+      switch (parent.type) {
+        // Control flow
+        case "IfStatement":
+        case "SwitchStatement":
+        case "TryStatement":
+        case "WhileStatement":
+        case "DoWhileStatement":
+        case "ForStatement":
+        case "ForInStatement":
+        case "ForOfStatement":
+          return false;
+
+        // Function
+        case "FunctionDeclaration":
+        case "FunctionExpression":
+        case "ArrowFunctionExpression":
+        case "ClassBody":
+          return false;
+
+        // Branch
+        case "LogicalExpression":
+        case "ConditionalExpression":
+        case "ChainExpression":
+          return false;
+
+        case "AssignmentExpression":
+          switch (parent.operator) {
+            // Branch
+            case "||=":
+            case "&&=":
+            case "??=":
+              return false;
+          }
+          break;
+
+        // Implicit branch (default value)
+        case "ObjectPattern":
+        case "ArrayPattern":
+          return false;
+      }
+    }
+    return true;
+  },
+
+  /**
+   * Check whether we might be in a test head file.
+   *
+   * @param  {RuleContext} scope
+   *         You should pass this from within a rule
+   *         e.g. helpers.getIsHeadFile(context)
+   *
+   * @return {Boolean}
+   *         True or false
+   */
+  getIsHeadFile(scope) {
+    var pathAndFilename = this.cleanUpPath(scope.getFilename());
+
+    return /.*[\\/]head(_.+)?\.js$/.test(pathAndFilename);
+  },
+
+  /**
+   * Gets the head files for a potential test file
+   *
+   * @param  {RuleContext} scope
+   *         You should pass this from within a rule
+   *         e.g. helpers.getIsHeadFile(context)
+   *
+   * @return {String[]}
+   *         Paths to head files to load for the test
+   */
+  getTestHeadFiles(scope) {
+    if (!this.getIsTest(scope)) {
+      return [];
+    }
+
+    let filepath = this.cleanUpPath(scope.getFilename());
+    let dir = path.dirname(filepath);
+
+    let names = fs
+      .readdirSync(dir)
+      .filter(
+        name =>
+          (name.startsWith("head") || name.startsWith("xpcshell-head")) &&
+          name.endsWith(".js")
+      )
+      .map(name => path.join(dir, name));
+    return names;
+  },
+
+  /**
+   * Gets all the test manifest data for a directory
+   *
+   * @param  {String} dir
+   *         The directory
+   *
+   * @return {Array}
+   *         An array of objects with file and manifest properties
+   */
+  getManifestsForDirectory(dir) {
+    if (directoryManifests.has(dir)) {
+      return directoryManifests.get(dir);
+    }
+
+    let manifests = [];
+    let names = [];
+    try {
+      names = fs.readdirSync(dir);
+    } catch (err) {
+      // Ignore directory not found, it might be faked by a test
+      if (err.code !== "ENOENT") {
+        throw err;
+      }
+    }
+
+    for (let name of names) {
+      if (!name.endsWith(".ini")) {
+        continue;
+      }
+
+      try {
+        let manifest = this.iniParser.parse(
+          fs.readFileSync(path.join(dir, name), "utf8").split("\n")
+        );
+        manifests.push({
+          file: path.join(dir, name),
+          manifest,
+        });
+      } catch (e) {}
+    }
+
+    directoryManifests.set(dir, manifests);
+    return manifests;
+  },
+
+  /**
+   * Gets the manifest file a test is listed in
+   *
+   * @param  {RuleContext} scope
+   *         You should pass this from within a rule
+   *         e.g. helpers.getIsHeadFile(context)
+   *
+   * @return {String}
+   *         The path to the test manifest file
+   */
+  getTestManifest(scope) {
+    let filepath = this.cleanUpPath(scope.getFilename());
+
+    let dir = path.dirname(filepath);
+    let filename = path.basename(filepath);
+
+    for (let manifest of this.getManifestsForDirectory(dir)) {
+      if (filename in manifest.manifest) {
+        return manifest.file;
+      }
+    }
+
+    return null;
+  },
+
+  /**
+   * Check whether we are in a test of some kind.
+   *
+   * @param  {RuleContext} scope
+   *         You should pass this from within a rule
+   *         e.g. helpers.getIsTest(context)
+   *
+   * @return {Boolean}
+   *         True or false
+   */
+  getIsTest(scope) {
+    // Regardless of the manifest name being in a manifest means we're a test.
+    let manifest = this.getTestManifest(scope);
+    if (manifest) {
+      return true;
+    }
+
+    return !!this.getTestType(scope);
+  },
+
+  /*
+   * Check if this is an .sjs file.
+   */
+  getIsSjs(scope) {
+    let filepath = this.cleanUpPath(scope.getFilename());
+
+    return path.extname(filepath) == ".sjs";
+  },
+
+  /**
+   * Gets the type of test or null if this isn't a test.
+   *
+   * @param  {RuleContext} scope
+   *         You should pass this from within a rule
+   *         e.g. helpers.getIsHeadFile(context)
+   *
+   * @return {String or null}
+   *         Test type: xpcshell, browser, chrome, mochitest
+   */
+  getTestType(scope) {
+    let testTypes = ["browser", "xpcshell", "chrome", "mochitest", "a11y"];
+    let manifest = this.getTestManifest(scope);
+    if (manifest) {
+      let name = path.basename(manifest);
+      for (let testType of testTypes) {
+        if (name.startsWith(testType)) {
+          return testType;
+        }
+      }
+    }
+
+    let filepath = this.cleanUpPath(scope.getFilename());
+    let filename = path.basename(filepath);
+
+    if (filename.startsWith("browser_")) {
+      return "browser";
+    }
+
+    if (filename.startsWith("test_")) {
+      let parent = path.basename(path.dirname(filepath));
+      for (let testType of testTypes) {
+        if (parent.startsWith(testType)) {
+          return testType;
+        }
+      }
+
+      // It likely is a test, we're just not sure what kind.
+      return "unknown";
+    }
+
+    // Likely not a test
+    return null;
+  },
+
+  getIsWorker(filePath) {
+    let filename = path.basename(this.cleanUpPath(filePath)).toLowerCase();
+
+    return filename.includes("worker");
+  },
+
+  /**
+   * Gets the root directory of the repository by walking up directories from
+   * this file until a .eslintignore file is found. If this fails, the same
+   * procedure will be attempted from the current working dir.
+   * @return {String} The absolute path of the repository directory
+   */
+  get rootDir() {
+    if (!gRootDir) {
+      function searchUpForIgnore(dirName, filename) {
+        let parsed = path.parse(dirName);
+        while (parsed.root !== dirName) {
+          if (fs.existsSync(path.join(dirName, filename))) {
+            return dirName;
+          }
+          // Move up a level
+          dirName = parsed.dir;
+          parsed = path.parse(dirName);
+        }
+        return null;
+      }
+
+      let possibleRoot = searchUpForIgnore(
+        path.dirname(module.filename),
+        ".eslintignore"
+      );
+      if (!possibleRoot) {
+        possibleRoot = searchUpForIgnore(path.resolve(), ".eslintignore");
+      }
+      if (!possibleRoot) {
+        possibleRoot = searchUpForIgnore(path.resolve(), "package.json");
+      }
+      if (!possibleRoot) {
+        // We've couldn't find a root from the module or CWD, so lets just go
+        // for the CWD. We really don't want to throw if possible, as that
+        // tends to give confusing results when used with ESLint.
+        possibleRoot = process.cwd();
+      }
+
+      gRootDir = possibleRoot;
+    }
+
+    return gRootDir;
+  },
+
+  /**
+   * ESLint may be executed from various places: from mach, at the root of the
+   * repository, or from a directory in the repository when, for instance,
+   * executed by a text editor's plugin.
+   * The value returned by context.getFileName() varies because of this.
+   * This helper function makes sure to return an absolute file path for the
+   * current context, by looking at process.cwd().
+   * @param {Context} context
+   * @return {String} The absolute path
+   */
+  getAbsoluteFilePath(context) {
+    var fileName = this.cleanUpPath(context.getFilename());
+    var cwd = process.cwd();
+
+    if (path.isAbsolute(fileName)) {
+      // Case 2: executed from the repo's root with mach:
+      //   fileName: /path/to/mozilla/repo/a/b/c/d.js
+      //   cwd: /path/to/mozilla/repo
+      return fileName;
+    } else if (path.basename(fileName) == fileName) {
+      // Case 1b: executed from a nested directory, fileName is the base name
+      // without any path info (happens in Atom with linter-eslint)
+      return path.join(cwd, fileName);
+    }
+    // Case 1: executed form in a nested directory, e.g. from a text editor:
+    //   fileName: a/b/c/d.js
+    //   cwd: /path/to/mozilla/repo/a/b/c
+    var dirName = path.dirname(fileName);
+    return cwd.slice(0, cwd.length - dirName.length) + fileName;
+  },
+
+  /**
+   * When ESLint is run from SublimeText, paths retrieved from
+   * context.getFileName contain leading and trailing double-quote characters.
+   * These characters need to be removed.
+   */
+  cleanUpPath(pathName) {
+    return pathName.replace(/^"/, "").replace(/"$/, "");
+  },
+
+  get globalScriptPaths() {
+    return [
+      path.join(this.rootDir, "browser", "base", "content", "browser.xhtml"),
+      path.join(
+        this.rootDir,
+        "browser",
+        "base",
+        "content",
+        "global-scripts.inc"
+      ),
+    ];
+  },
+
+  isMozillaCentralBased() {
+    return fs.existsSync(this.globalScriptPaths[0]);
+  },
+
+  getSavedEnvironmentItems(environment) {
+    return require("./environments/saved-globals.json").environments[
+      environment
+    ];
+  },
+
+  getSavedRuleData(rule) {
+    return require("./rules/saved-rules-data.json").rulesData[rule];
+  },
+
+  getBuildEnvironment() {
+    var { execFileSync } = require("child_process");
+    var output = execFileSync(
+      path.join(this.rootDir, "mach"),
+      ["environment", "--format=json"],
+      { silent: true }
+    );
+    return JSON.parse(output);
+  },
+
+  /**
+   * Extract the path of require (and require-like) helpers used in DevTools.
+   */
+  getDevToolsRequirePath(node) {
+    if (
+      node.callee.type == "Identifier" &&
+      node.callee.name == "require" &&
+      node.arguments.length == 1 &&
+      node.arguments[0].type == "Literal"
+    ) {
+      return node.arguments[0].value;
+    } else if (
+      node.callee.type == "MemberExpression" &&
+      node.callee.property.type == "Identifier" &&
+      node.callee.property.name == "lazyRequireGetter" &&
+      node.arguments.length >= 3 &&
+      node.arguments[2].type == "Literal"
+    ) {
+      return node.arguments[2].value;
+    }
+    return null;
+  },
+
+  /**
+   * Returns property name from MemberExpression. Also accepts Identifier for consistency.
+   * @param {import("estree").MemberExpression | import("estree").Identifier} node
+   * @returns {string | null}
+   *
+   * @example `foo` gives "foo"
+   * @example `foo.bar` gives "bar"
+   * @example `foo.bar.baz` gives "baz"
+   */
+  maybeGetMemberPropertyName(node) {
+    if (node.type === "MemberExpression") {
+      return node.property.name;
+    }
+    if (node.type === "Identifier") {
+      return node.name;
+    }
+    return null;
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/index.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/index.js
new file mode 100644
index 0000000000..aad6d8bbbd
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/index.js
@@ -0,0 +1,96 @@
+/**
+ * @fileoverview A collection of rules that help enforce JavaScript coding
+ * standard and avoid common errors in the Mozilla project.
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+// ------------------------------------------------------------------------------
+// Plugin Definition
+// ------------------------------------------------------------------------------
+module.exports = {
+  configs: {
+    "browser-test": require("../lib/configs/browser-test"),
+    "chrome-test": require("../lib/configs/chrome-test"),
+    "mochitest-test": require("../lib/configs/mochitest-test"),
+    recommended: require("../lib/configs/recommended"),
+    "require-jsdoc": require("../lib/configs/require-jsdoc"),
+    "valid-jsdoc": require("../lib/configs/valid-jsdoc"),
+    "xpcshell-test": require("../lib/configs/xpcshell-test"),
+  },
+  environments: {
+    "browser-window": require("../lib/environments/browser-window.js"),
+    "chrome-script": require("../lib/environments/chrome-script.js"),
+    "chrome-worker": require("../lib/environments/chrome-worker.js"),
+    "frame-script": require("../lib/environments/frame-script.js"),
+    jsm: require("../lib/environments/jsm.js"),
+    "process-script": require("../lib/environments/process-script.js"),
+    "remote-page": require("../lib/environments/remote-page.js"),
+    simpletest: require("../lib/environments/simpletest.js"),
+    sjs: require("../lib/environments/sjs.js"),
+    "special-powers-sandbox": require("../lib/environments/special-powers-sandbox.js"),
+    specific: require("../lib/environments/specific"),
+    privileged: require("../lib/environments/privileged.js"),
+    xpcshell: require("../lib/environments/xpcshell.js"),
+  },
+  rules: {
+    "avoid-Date-timing": require("../lib/rules/avoid-Date-timing"),
+    "avoid-removeChild": require("../lib/rules/avoid-removeChild"),
+    "balanced-listeners": require("../lib/rules/balanced-listeners"),
+    "balanced-observers": require("../lib/rules/balanced-observers"),
+    "consistent-if-bracing": require("../lib/rules/consistent-if-bracing"),
+    "import-browser-window-globals": require("../lib/rules/import-browser-window-globals"),
+    "import-content-task-globals": require("../lib/rules/import-content-task-globals"),
+    "import-globals": require("../lib/rules/import-globals"),
+    "import-headjs-globals": require("../lib/rules/import-headjs-globals"),
+    "lazy-getter-object-name": require("../lib/rules/lazy-getter-object-name"),
+    "mark-exported-symbols-as-used": require("../lib/rules/mark-exported-symbols-as-used"),
+    "mark-test-function-used": require("../lib/rules/mark-test-function-used"),
+    "no-aArgs": require("../lib/rules/no-aArgs"),
+    "no-addtask-setup": require("../lib/rules/no-addtask-setup"),
+    "no-arbitrary-setTimeout": require("../lib/rules/no-arbitrary-setTimeout"),
+    "no-compare-against-boolean-literals": require("../lib/rules/no-compare-against-boolean-literals"),
+    "no-cu-reportError": require("../lib/rules/no-cu-reportError"),
+    "no-define-cc-etc": require("../lib/rules/no-define-cc-etc"),
+    "no-redeclare-with-import-autofix": require("../lib/rules/no-redeclare-with-import-autofix"),
+    "no-throw-cr-literal": require("../lib/rules/no-throw-cr-literal"),
+    "no-useless-parameters": require("../lib/rules/no-useless-parameters"),
+    "no-useless-removeEventListener": require("../lib/rules/no-useless-removeEventListener"),
+    "no-useless-run-test": require("../lib/rules/no-useless-run-test"),
+    "prefer-boolean-length-check": require("../lib/rules/prefer-boolean-length-check"),
+    "prefer-formatValues": require("../lib/rules/prefer-formatValues"),
+    "reject-addtask-only": require("../lib/rules/reject-addtask-only"),
+    "reject-chromeutils-import-params": require("../lib/rules/reject-chromeutils-import-params"),
+    "reject-eager-module-in-lazy-getter": require("../lib/rules/reject-eager-module-in-lazy-getter"),
+    "reject-global-this": require("../lib/rules/reject-global-this"),
+    "reject-globalThis-modification": require("../lib/rules/reject-globalThis-modification"),
+    "reject-import-system-module-from-non-system": require("../lib/rules/reject-import-system-module-from-non-system"),
+    "reject-importGlobalProperties": require("../lib/rules/reject-importGlobalProperties"),
+    "reject-lazy-imports-into-globals": require("../lib/rules/reject-lazy-imports-into-globals"),
+    "reject-mixing-eager-and-lazy": require("../lib/rules/reject-mixing-eager-and-lazy"),
+    "reject-multiple-getters-calls": require("../lib/rules/reject-multiple-getters-calls"),
+    "reject-scriptableunicodeconverter": require("../lib/rules/reject-scriptableunicodeconverter"),
+    "reject-relative-requires": require("../lib/rules/reject-relative-requires"),
+    "reject-some-requires": require("../lib/rules/reject-some-requires"),
+    "reject-top-level-await": require("../lib/rules/reject-top-level-await"),
+    "rejects-requires-await": require("../lib/rules/rejects-requires-await"),
+    "use-cc-etc": require("../lib/rules/use-cc-etc"),
+    "use-chromeutils-generateqi": require("../lib/rules/use-chromeutils-generateqi"),
+    "use-chromeutils-import": require("../lib/rules/use-chromeutils-import"),
+    "use-default-preference-values": require("../lib/rules/use-default-preference-values"),
+    "use-ownerGlobal": require("../lib/rules/use-ownerGlobal"),
+    "use-includes-instead-of-indexOf": require("../lib/rules/use-includes-instead-of-indexOf"),
+    "use-isInstance": require("./rules/use-isInstance"),
+    "use-returnValue": require("../lib/rules/use-returnValue"),
+    "use-services": require("../lib/rules/use-services"),
+    "use-static-import": require("../lib/rules/use-static-import"),
+    "valid-ci-uses": require("../lib/rules/valid-ci-uses"),
+    "valid-lazy": require("../lib/rules/valid-lazy"),
+    "valid-services": require("../lib/rules/valid-services"),
+    "valid-services-property": require("../lib/rules/valid-services-property"),
+    "var-only-at-top-level": require("../lib/rules/var-only-at-top-level"),
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/avoid-Date-timing.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/avoid-Date-timing.js
new file mode 100644
index 0000000000..ce576e9483
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/avoid-Date-timing.js
@@ -0,0 +1,61 @@
+/**
+ * @fileoverview Disallow using Date for timing in performance sensitive code
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+module.exports = {
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/avoid-Date-timing.html",
+    },
+    messages: {
+      usePerfNow:
+        "use performance.now() instead of Date.now() for timing measurements",
+    },
+    schema: [],
+    type: "problem",
+  },
+
+  create(context) {
+    return {
+      CallExpression(node) {
+        let callee = node.callee;
+        if (
+          callee.type !== "MemberExpression" ||
+          callee.object.type !== "Identifier" ||
+          callee.object.name !== "Date" ||
+          callee.property.type !== "Identifier" ||
+          callee.property.name !== "now"
+        ) {
+          return;
+        }
+
+        context.report({
+          node,
+          messageId: "usePerfNow",
+        });
+      },
+
+      NewExpression(node) {
+        let callee = node.callee;
+        if (
+          callee.type !== "Identifier" ||
+          callee.name !== "Date" ||
+          node.arguments.length
+        ) {
+          return;
+        }
+
+        context.report({
+          node,
+          messageId: "usePerfNow",
+        });
+      },
+    };
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/avoid-removeChild.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/avoid-removeChild.js
new file mode 100644
index 0000000000..7db4afdde1
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/avoid-removeChild.js
@@ -0,0 +1,70 @@
+/**
+ * @fileoverview Reject using element.parentNode.removeChild(element) when
+ *               element.remove() can be used instead.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+var helpers = require("../helpers");
+
+module.exports = {
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/avoid-removeChild.html",
+    },
+    messages: {
+      useRemove:
+        "use element.remove() instead of element.parentNode.removeChild(element)",
+      useFirstChildRemove:
+        "use element.firstChild.remove() instead of element.removeChild(element.firstChild)",
+    },
+    schema: [],
+    type: "suggestion",
+  },
+
+  create(context) {
+    return {
+      CallExpression(node) {
+        let callee = node.callee;
+        if (
+          callee.type !== "MemberExpression" ||
+          callee.property.type !== "Identifier" ||
+          callee.property.name != "removeChild" ||
+          node.arguments.length != 1
+        ) {
+          return;
+        }
+
+        if (
+          callee.object.type == "MemberExpression" &&
+          callee.object.property.type == "Identifier" &&
+          callee.object.property.name == "parentNode" &&
+          helpers.getASTSource(callee.object.object, context) ==
+            helpers.getASTSource(node.arguments[0])
+        ) {
+          context.report({
+            node,
+            messageId: "useRemove",
+          });
+        }
+
+        if (
+          node.arguments[0].type == "MemberExpression" &&
+          node.arguments[0].property.type == "Identifier" &&
+          node.arguments[0].property.name == "firstChild" &&
+          helpers.getASTSource(callee.object, context) ==
+            helpers.getASTSource(node.arguments[0].object)
+        ) {
+          context.report({
+            node,
+            messageId: "useFirstChildRemove",
+          });
+        }
+      },
+    };
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/balanced-listeners.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/balanced-listeners.js
new file mode 100644
index 0000000000..d571918909
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/balanced-listeners.js
@@ -0,0 +1,149 @@
+/**
+ * @fileoverview Check that there's a removeEventListener for each
+ * addEventListener and an off for each on.
+ * Note that for now, this rule is rather simple in that it only checks that
+ * for each event name there is both an add and remove listener. It doesn't
+ * check that these are called on the right objects or with the same callback.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+module.exports = {
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/balanced-listeners.html",
+    },
+    messages: {
+      noCorresponding:
+        "No corresponding '{{functionName}}({{type}})' was found.",
+    },
+    schema: [],
+    type: "problem",
+  },
+
+  create(context) {
+    var DICTIONARY = {
+      addEventListener: "removeEventListener",
+      on: "off",
+    };
+    // Invert this dictionary to make it easy later.
+    var INVERTED_DICTIONARY = {};
+    for (var i in DICTIONARY) {
+      INVERTED_DICTIONARY[DICTIONARY[i]] = i;
+    }
+
+    // Collect the add/remove listeners in these 2 arrays.
+    var addedListeners = [];
+    var removedListeners = [];
+
+    function addAddedListener(node) {
+      var capture = false;
+      let options = node.arguments[2];
+      if (options) {
+        if (options.type == "ObjectExpression") {
+          if (
+            options.properties.some(
+              p => p.key.name == "once" && p.value.value === true
+            )
+          ) {
+            // No point in adding listeners using the 'once' option.
+            return;
+          }
+          capture = options.properties.some(
+            p => p.key.name == "capture" && p.value.value === true
+          );
+        } else {
+          capture = options.value;
+        }
+      }
+      addedListeners.push({
+        functionName: node.callee.property.name,
+        type: node.arguments[0].value,
+        node: node.callee.property,
+        useCapture: capture,
+      });
+    }
+
+    function addRemovedListener(node) {
+      var capture = false;
+      let options = node.arguments[2];
+      if (options) {
+        if (options.type == "ObjectExpression") {
+          capture = options.properties.some(
+            p => p.key.name == "capture" && p.value.value === true
+          );
+        } else {
+          capture = options.value;
+        }
+      }
+      removedListeners.push({
+        functionName: node.callee.property.name,
+        type: node.arguments[0].value,
+        useCapture: capture,
+      });
+    }
+
+    function getUnbalancedListeners() {
+      var unbalanced = [];
+
+      for (var j = 0; j < addedListeners.length; j++) {
+        if (!hasRemovedListener(addedListeners[j])) {
+          unbalanced.push(addedListeners[j]);
+        }
+      }
+      addedListeners = removedListeners = [];
+
+      return unbalanced;
+    }
+
+    function hasRemovedListener(addedListener) {
+      for (var k = 0; k < removedListeners.length; k++) {
+        var listener = removedListeners[k];
+        if (
+          DICTIONARY[addedListener.functionName] === listener.functionName &&
+          addedListener.type === listener.type &&
+          addedListener.useCapture === listener.useCapture
+        ) {
+          return true;
+        }
+      }
+
+      return false;
+    }
+
+    return {
+      CallExpression(node) {
+        if (node.arguments.length === 0) {
+          return;
+        }
+
+        if (node.callee.type === "MemberExpression") {
+          var listenerMethodName = node.callee.property.name;
+
+          if (DICTIONARY.hasOwnProperty(listenerMethodName)) {
+            addAddedListener(node);
+          } else if (INVERTED_DICTIONARY.hasOwnProperty(listenerMethodName)) {
+            addRemovedListener(node);
+          }
+        }
+      },
+
+      "Program:exit": function () {
+        getUnbalancedListeners().forEach(function (listener) {
+          context.report({
+            node: listener.node,
+            messageId: "noCorresponding",
+            data: {
+              functionName: DICTIONARY[listener.functionName],
+              type: listener.type,
+            },
+          });
+        });
+      },
+    };
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/balanced-observers.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/balanced-observers.js
new file mode 100644
index 0000000000..6003b1c08a
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/balanced-observers.js
@@ -0,0 +1,121 @@
+/**
+ * @fileoverview Check that there's a Services.(prefs|obs).removeObserver for
+ * each addObserver.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+module.exports = {
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/balanced-observers.html",
+    },
+    messages: {
+      noCorresponding:
+        "No corresponding 'removeObserver(\"{{observable}}\")' was found.",
+    },
+    schema: [],
+    type: "problem",
+  },
+
+  create(context) {
+    var addedObservers = [];
+    var removedObservers = [];
+
+    function getObserverAPI(node) {
+      const object = node.callee.object;
+      if (
+        object.type == "MemberExpression" &&
+        object.property.type == "Identifier"
+      ) {
+        return object.property.name;
+      }
+      return null;
+    }
+
+    function isServicesObserver(api) {
+      return api == "obs" || api == "prefs";
+    }
+
+    function getObservableName(node, api) {
+      if (api === "obs") {
+        return node.arguments[1].value;
+      }
+      return node.arguments[0].value;
+    }
+
+    function addAddedObserver(node) {
+      const api = getObserverAPI(node);
+      if (!isServicesObserver(api)) {
+        return;
+      }
+
+      addedObservers.push({
+        functionName: node.callee.property.name,
+        observable: getObservableName(node, api),
+        node: node.callee.property,
+      });
+    }
+
+    function addRemovedObserver(node) {
+      const api = getObserverAPI(node);
+      if (!isServicesObserver(api)) {
+        return;
+      }
+
+      removedObservers.push({
+        functionName: node.callee.property.name,
+        observable: getObservableName(node, api),
+      });
+    }
+
+    function getUnbalancedObservers() {
+      const unbalanced = addedObservers.filter(
+        observer => !hasRemovedObserver(observer)
+      );
+      addedObservers = removedObservers = [];
+
+      return unbalanced;
+    }
+
+    function hasRemovedObserver(addedObserver) {
+      return removedObservers.some(
+        observer => addedObserver.observable === observer.observable
+      );
+    }
+
+    return {
+      CallExpression(node) {
+        if (node.arguments.length === 0) {
+          return;
+        }
+
+        if (node.callee.type === "MemberExpression") {
+          var methodName = node.callee.property.name;
+
+          if (methodName === "addObserver") {
+            addAddedObserver(node);
+          } else if (methodName === "removeObserver") {
+            addRemovedObserver(node);
+          }
+        }
+      },
+
+      "Program:exit": function () {
+        getUnbalancedObservers().forEach(function (observer) {
+          context.report({
+            node: observer.node,
+            messageId: "noCorresponding",
+            data: {
+              observable: observer.observable,
+            },
+          });
+        });
+      },
+    };
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/consistent-if-bracing.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/consistent-if-bracing.js
new file mode 100644
index 0000000000..6e3629833c
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/consistent-if-bracing.js
@@ -0,0 +1,54 @@
+/**
+ * @fileoverview checks if/else if/else bracing is consistent
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+module.exports = {
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/consistent-if-bracing.html",
+    },
+    messages: {
+      consistentIfBracing: "Bracing of if..else bodies should be consistent.",
+    },
+    schema: [],
+    type: "layout",
+  },
+
+  create(context) {
+    return {
+      IfStatement(node) {
+        if (node.parent.type !== "IfStatement") {
+          let types = new Set();
+          for (
+            let currentNode = node;
+            currentNode;
+            currentNode = currentNode.alternate
+          ) {
+            let type = currentNode.consequent.type;
+            types.add(type == "BlockStatement" ? "Block" : "NotBlock");
+            if (
+              currentNode.alternate &&
+              currentNode.alternate.type !== "IfStatement"
+            ) {
+              type = currentNode.alternate.type;
+              types.add(type == "BlockStatement" ? "Block" : "NotBlock");
+              break;
+            }
+          }
+          if (types.size > 1) {
+            context.report({
+              node,
+              messageId: "consistentIfBracing",
+            });
+          }
+        }
+      },
+    };
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/import-browser-window-globals.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/import-browser-window-globals.js
new file mode 100644
index 0000000000..5ab19a2b0a
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/import-browser-window-globals.js
@@ -0,0 +1,50 @@
+/**
+ * @fileoverview For scripts included in browser-window, this will automatically
+ *               inject the browser-window global scopes into the file.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+var path = require("path");
+var helpers = require("../helpers");
+var browserWindowEnv = require("../environments/browser-window");
+
+module.exports = {
+  // This rule currently has no messages.
+  // eslint-disable-next-line eslint-plugin/prefer-message-ids
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/import-browser-window-globals.html",
+    },
+    schema: [],
+    type: "problem",
+  },
+
+  create(context) {
+    return {
+      Program(node) {
+        let filePath = helpers.getAbsoluteFilePath(context);
+        let relativePath = path.relative(helpers.rootDir, filePath);
+        // We need to translate the path on Windows, due to the change
+        // from \ to /, and browserjsScripts assumes Posix.
+        if (path.win32) {
+          relativePath = relativePath.split(path.sep).join("/");
+        }
+
+        if (browserWindowEnv.browserjsScripts?.includes(relativePath)) {
+          for (let global in browserWindowEnv.globals) {
+            helpers.addVarToScope(
+              global,
+              context.getScope(),
+              browserWindowEnv.globals[global]
+            );
+          }
+        }
+      },
+    };
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/import-content-task-globals.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/import-content-task-globals.js
new file mode 100644
index 0000000000..75d11bcd59
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/import-content-task-globals.js
@@ -0,0 +1,73 @@
+/**
+ * @fileoverview For ContentTask.spawn, this will automatically declare the
+ *               frame script variables in the global scope.
+ *               Note: due to the way ESLint works, it appears it is only
+ *               easy to declare these variables on a file-global scope, rather
+ *               than function global.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+var helpers = require("../helpers");
+var frameScriptEnv = require("../environments/frame-script");
+var sandboxEnv = require("../environments/special-powers-sandbox");
+
+module.exports = {
+  // eslint-disable-next-line eslint-plugin/prefer-message-ids
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/import-content-task-globals.html",
+    },
+    schema: [],
+    type: "problem",
+  },
+
+  create(context) {
+    return {
+      "CallExpression[callee.object.name='ContentTask'][callee.property.name='spawn']":
+        function (node) {
+          // testing/mochitest/BrowserTestUtils/content/content-task.js
+          // This script is loaded as a sub script into a frame script.
+          for (let [name, value] of Object.entries(frameScriptEnv.globals)) {
+            helpers.addVarToScope(name, context.getScope(), value);
+          }
+        },
+      "CallExpression[callee.object.name='SpecialPowers'][callee.property.name='spawn']":
+        function (node) {
+          for (let [name, value] of Object.entries(sandboxEnv.globals)) {
+            helpers.addVarToScope(name, context.getScope(), value);
+          }
+          let globals = [
+            // testing/specialpowers/content/SpecialPowersChild.sys.mjs
+            // SpecialPowersChild._spawnTask
+            "SpecialPowers",
+            "ContentTaskUtils",
+            "content",
+            "docShell",
+          ];
+          for (let global of globals) {
+            helpers.addVarToScope(global, context.getScope(), false);
+          }
+        },
+      "CallExpression[callee.object.name='SpecialPowers'][callee.property.name='spawnChrome']":
+        function (node) {
+          for (let [name, value] of Object.entries(sandboxEnv.globals)) {
+            helpers.addVarToScope(name, context.getScope(), value);
+          }
+          let globals = [
+            // testing/specialpowers/content/SpecialPowersParent.sys.mjs
+            // SpecialPowersParent._spawnChrome
+            "windowGlobalParent",
+            "browsingContext",
+          ];
+          for (let global of globals) {
+            helpers.addVarToScope(global, context.getScope(), false);
+          }
+        },
+    };
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/import-globals.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/import-globals.js
new file mode 100644
index 0000000000..a62cf008ea
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/import-globals.js
@@ -0,0 +1,21 @@
+/**
+ * @fileoverview Discovers all globals for the current file.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+module.exports = {
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/import-globals.html",
+    },
+    schema: [],
+    type: "problem",
+  },
+
+  create: require("../globals").getESLintGlobalParser,
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/import-headjs-globals.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/import-headjs-globals.js
new file mode 100644
index 0000000000..2566b3cec0
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/import-headjs-globals.js
@@ -0,0 +1,51 @@
+/**
+ * @fileoverview Import globals from head.js and from any files that were
+ * imported by head.js (as far as we can correctly resolve the path).
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+var fs = require("fs");
+var helpers = require("../helpers");
+var globals = require("../globals");
+
+function importHead(context, path, node) {
+  try {
+    let stats = fs.statSync(path);
+    if (!stats.isFile()) {
+      return;
+    }
+  } catch (e) {
+    return;
+  }
+
+  let newGlobals = globals.getGlobalsForFile(path);
+  helpers.addGlobals(newGlobals, context.getScope());
+}
+
+module.exports = {
+  // This rule currently has no messages.
+  // eslint-disable-next-line eslint-plugin/prefer-message-ids
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/import-headjs-globals.html",
+    },
+    schema: [],
+    type: "problem",
+  },
+
+  create(context) {
+    return {
+      Program(node) {
+        let heads = helpers.getTestHeadFiles(context);
+        for (let head of heads) {
+          importHead(context, head, node);
+        }
+      },
+    };
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/lazy-getter-object-name.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/lazy-getter-object-name.js
new file mode 100644
index 0000000000..2bacac3904
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/lazy-getter-object-name.js
@@ -0,0 +1,48 @@
+/**
+ * @fileoverview Enforce the standard object name for
+ * ChromeUtils.defineESModuleGetters
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+function isIdentifier(node, id) {
+  return node.type === "Identifier" && node.name === id;
+}
+
+module.exports = {
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/lazy-getter-object-name.html",
+    },
+    messages: {
+      mustUseLazy:
+        "The variable name of the object passed to ChromeUtils.defineESModuleGetters must be `lazy`",
+    },
+    schema: [],
+    type: "problem",
+  },
+
+  create(context) {
+    return {
+      CallExpression(node) {
+        let { callee } = node;
+        if (
+          callee.type === "MemberExpression" &&
+          isIdentifier(callee.object, "ChromeUtils") &&
+          isIdentifier(callee.property, "defineESModuleGetters") &&
+          node.arguments.length >= 1 &&
+          !isIdentifier(node.arguments[0], "lazy")
+        ) {
+          context.report({
+            node,
+            messageId: "mustUseLazy",
+          });
+        }
+      },
+    };
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/mark-exported-symbols-as-used.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/mark-exported-symbols-as-used.js
new file mode 100644
index 0000000000..17e29e4cd1
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/mark-exported-symbols-as-used.js
@@ -0,0 +1,90 @@
+/**
+ * @fileoverview Simply marks exported symbols as used. Designed for use in
+ * .jsm files only.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+function markArrayElementsAsUsed(context, node, expression) {
+  if (expression.type != "ArrayExpression") {
+    context.report({
+      node,
+      messageId: "nonArrayAssignedToImported",
+    });
+    return;
+  }
+
+  for (let element of expression.elements) {
+    context.markVariableAsUsed(element.value);
+  }
+  // Also mark EXPORTED_SYMBOLS as used.
+  context.markVariableAsUsed("EXPORTED_SYMBOLS");
+}
+
+// Ignore assignments not in the global scope, e.g. where special module
+// definitions are required due to having different ways of importing files,
+// e.g. osfile.
+function isGlobalScope(context) {
+  return !context.getScope().upper;
+}
+
+module.exports = {
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/mark-exported-symbols-as-used.html",
+    },
+    messages: {
+      useLetForExported:
+        "EXPORTED_SYMBOLS cannot be declared via `let`. Use `var` or `this.EXPORTED_SYMBOLS =`",
+      nonArrayAssignedToImported:
+        "Unexpected assignment of non-Array to EXPORTED_SYMBOLS",
+    },
+    schema: [],
+    type: "problem",
+  },
+
+  create(context) {
+    return {
+      AssignmentExpression(node, parents) {
+        if (
+          node.operator === "=" &&
+          node.left.type === "MemberExpression" &&
+          node.left.object.type === "ThisExpression" &&
+          node.left.property.name === "EXPORTED_SYMBOLS" &&
+          isGlobalScope(context)
+        ) {
+          markArrayElementsAsUsed(context, node, node.right);
+        }
+      },
+
+      VariableDeclaration(node, parents) {
+        if (!isGlobalScope(context)) {
+          return;
+        }
+
+        for (let item of node.declarations) {
+          if (
+            item.id &&
+            item.id.type == "Identifier" &&
+            item.id.name === "EXPORTED_SYMBOLS"
+          ) {
+            if (node.kind === "let") {
+              // The use of 'let' isn't allowed as the lexical scope may die after
+              // the script executes.
+              context.report({
+                node,
+                messageId: "useLetForExported",
+              });
+            }
+
+            markArrayElementsAsUsed(context, node, item.init);
+          }
+        }
+      },
+    };
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/mark-test-function-used.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/mark-test-function-used.js
new file mode 100644
index 0000000000..1e7bfdc5f4
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/mark-test-function-used.js
@@ -0,0 +1,44 @@
+/**
+ * @fileoverview Simply marks `test` (the test method) or `run_test` as used
+ * when in mochitests or xpcshell tests respectively. This avoids ESLint telling
+ * us that the function is never called.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+var helpers = require("../helpers");
+
+module.exports = {
+  // This rule currently has no messages.
+  // eslint-disable-next-line eslint-plugin/prefer-message-ids
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/mark-test-function-used.html",
+    },
+    schema: [],
+    type: "problem",
+  },
+
+  create(context) {
+    return {
+      Program() {
+        let testType = helpers.getTestType(context);
+        if (testType == "browser") {
+          context.markVariableAsUsed("test");
+        }
+
+        if (testType == "xpcshell") {
+          context.markVariableAsUsed("run_test");
+        }
+
+        if (helpers.getIsSjs(context)) {
+          context.markVariableAsUsed("handleRequest");
+        }
+      },
+    };
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/no-aArgs.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/no-aArgs.js
new file mode 100644
index 0000000000..19a4da6472
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/no-aArgs.js
@@ -0,0 +1,57 @@
+/**
+ * @fileoverview warns against using hungarian notation in function arguments
+ * (i.e. aArg).
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+function isPrefixed(name) {
+  return name.length >= 2 && /^a[A-Z]/.test(name);
+}
+
+function deHungarianize(name) {
+  return name.substring(1, 2).toLowerCase() + name.substring(2, name.length);
+}
+
+module.exports = {
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/no-aArgs.html",
+    },
+    messages: {
+      dontUseHungarian:
+        "Parameter '{{name}}' uses Hungarian Notation, consider using '{{suggestion}}' instead.",
+    },
+    schema: [],
+    type: "layout",
+  },
+
+  create(context) {
+    function checkFunction(node) {
+      for (var i = 0; i < node.params.length; i++) {
+        var param = node.params[i];
+        if (param.name && isPrefixed(param.name)) {
+          var errorObj = {
+            name: param.name,
+            suggestion: deHungarianize(param.name),
+          };
+          context.report({
+            node: param,
+            messageId: "dontUseHungarian",
+            data: errorObj,
+          });
+        }
+      }
+    }
+
+    return {
+      FunctionDeclaration: checkFunction,
+      ArrowFunctionExpression: checkFunction,
+      FunctionExpression: checkFunction,
+    };
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/no-addtask-setup.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/no-addtask-setup.js
new file mode 100644
index 0000000000..0289ae941d
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/no-addtask-setup.js
@@ -0,0 +1,57 @@
+/**
+ * @fileoverview Reject `add_task(async function setup` or similar patterns in
+ * favour of add_setup.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+function isNamedLikeSetup(name) {
+  return /^(init|setup)$/i.test(name);
+}
+
+module.exports = {
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/no-addtask-setup.html",
+    },
+    fixable: "code",
+    messages: {
+      useAddSetup: "Do not use add_task() for setup, use add_setup() instead.",
+    },
+    schema: [],
+    type: "suggestion",
+  },
+  create(context) {
+    return {
+      "Program > ExpressionStatement > CallExpression": function (node) {
+        let callee = node.callee;
+        if (callee.type === "Identifier" && callee.name === "add_task") {
+          let arg = node.arguments[0];
+          if (
+            arg.type !== "FunctionExpression" ||
+            !arg.id ||
+            !isNamedLikeSetup(arg.id.name)
+          ) {
+            return;
+          }
+          context.report({
+            node,
+            messageId: "useAddSetup",
+            fix: fixer => {
+              let range = [node.callee.range[0], arg.id.range[1]];
+              let asyncOrNot = arg.async ? "async " : "";
+              return fixer.replaceTextRange(
+                range,
+                `add_setup(${asyncOrNot}function`
+              );
+            },
+          });
+        }
+      },
+    };
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/no-arbitrary-setTimeout.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/no-arbitrary-setTimeout.js
new file mode 100644
index 0000000000..1888aff916
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/no-arbitrary-setTimeout.js
@@ -0,0 +1,65 @@
+/**
+ * @fileoverview Reject use of non-zero values in setTimeout
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+var helpers = require("../helpers");
+var testTypes = new Set(["browser", "xpcshell"]);
+
+module.exports = {
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/no-arbitrary-setTimeout.html",
+    },
+    messages: {
+      listenForEvents:
+        "listen for events instead of setTimeout() with arbitrary delay",
+    },
+    schema: [],
+    type: "problem",
+  },
+
+  create(context) {
+    // We don't want to run this on mochitest plain as it already
+    // prevents flaky setTimeout at runtime. This check is built-in
+    // to the rule itself as sometimes other tests can live alongside
+    // plain mochitests and so it can't be configured via eslintrc.
+    if (!testTypes.has(helpers.getTestType(context))) {
+      return {};
+    }
+
+    return {
+      CallExpression(node) {
+        let callee = node.callee;
+        if (callee.type === "MemberExpression") {
+          if (
+            callee.property.name !== "setTimeout" ||
+            callee.object.name !== "window" ||
+            node.arguments.length < 2
+          ) {
+            return;
+          }
+        } else if (callee.type === "Identifier") {
+          if (callee.name !== "setTimeout" || node.arguments.length < 2) {
+            return;
+          }
+        } else {
+          return;
+        }
+
+        let timeout = node.arguments[1];
+        if (timeout.type !== "Literal" || timeout.value > 0) {
+          context.report({
+            node,
+            messageId: "listenForEvents",
+          });
+        }
+      },
+    };
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/no-compare-against-boolean-literals.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/no-compare-against-boolean-literals.js
new file mode 100644
index 0000000000..0dc986685a
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/no-compare-against-boolean-literals.js
@@ -0,0 +1,40 @@
+/**
+ * @fileoverview Restrict comparing against `true` or `false`.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+module.exports = {
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/no-compare-against-boolean-literals.html",
+    },
+    messages: {
+      noCompareBoolean:
+        "Don't compare for inexact equality against boolean literals",
+    },
+    schema: [],
+    type: "suggestion",
+  },
+
+  create(context) {
+    return {
+      BinaryExpression(node) {
+        if (
+          ["==", "!="].includes(node.operator) &&
+          (["true", "false"].includes(node.left.raw) ||
+            ["true", "false"].includes(node.right.raw))
+        ) {
+          context.report({
+            node,
+            messageId: "noCompareBoolean",
+          });
+        }
+      },
+    };
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/no-cu-reportError.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/no-cu-reportError.js
new file mode 100644
index 0000000000..ad2d01a10a
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/no-cu-reportError.js
@@ -0,0 +1,130 @@
+/**
+ * @fileoverview Reject common XPCOM methods called with useless optional
+ *               parameters, or non-existent parameters.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+function isCuReportError(node) {
+  return (
+    node.type == "MemberExpression" &&
+    node.object.type == "Identifier" &&
+    node.object.name == "Cu" &&
+    node.property.type == "Identifier" &&
+    node.property.name == "reportError"
+  );
+}
+
+function isConcatenation(node) {
+  return node.type == "BinaryExpression" && node.operator == "+";
+}
+
+function isIdentOrMember(node) {
+  return node.type == "MemberExpression" || node.type == "Identifier";
+}
+
+function isLiteralOrConcat(node) {
+  return node.type == "Literal" || isConcatenation(node);
+}
+
+function replaceConcatWithComma(fixer, node) {
+  let fixes = [];
+  let didFixTrailingIdentifier = false;
+  let recursiveFixes;
+  let trailingIdentifier;
+  // Deal with recursion first:
+  if (isConcatenation(node.right)) {
+    // Uh oh. If the RHS is a concatenation, there are parens involved,
+    // e.g.:
+    // console.error("literal" + (b + "literal"));
+    // It's pretty much impossible to guess what to do here so bail out:
+    return { fixes: [], trailingIdentifier: false };
+  }
+  if (isConcatenation(node.left)) {
+    ({ fixes: recursiveFixes, trailingIdentifier } = replaceConcatWithComma(
+      fixer,
+      node.left
+    ));
+    fixes.push(...recursiveFixes);
+  }
+  // If the left is an identifier or memberexpression, and the right is a
+  // literal or concatenation - or vice versa - replace a + with a comma:
+  if (
+    (isIdentOrMember(node.left) && isLiteralOrConcat(node.right)) ||
+    (isIdentOrMember(node.right) && isLiteralOrConcat(node.left)) ||
+    // Or if the rhs is a literal/concatenation, while the right-most part of
+    // the lhs is also an identifier (need 2 commas either side!)
+    (trailingIdentifier && isLiteralOrConcat(node.right))
+  ) {
+    fixes.push(
+      fixer.replaceTextRange([node.left.range[1], node.right.range[0]], ", ")
+    );
+    didFixTrailingIdentifier = isIdentOrMember(node.right);
+  }
+  return { fixes, trailingIdentifier: didFixTrailingIdentifier };
+}
+
+module.exports = {
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/no-cu-reportError.html",
+    },
+    fixable: "code",
+    messages: {
+      useConsoleError: "Please use console.error instead of Cu.reportError",
+    },
+    schema: [],
+    type: "suggestion",
+  },
+
+  create(context) {
+    return {
+      CallExpression(node) {
+        let checkNodes = [];
+        if (isCuReportError(node.callee)) {
+          // Handles cases of `Cu.reportError()`.
+          if (node.arguments.length > 1) {
+            // TODO: Bug 1802347 For initial landing, we allow the two
+            // argument form of Cu.reportError as the second argument is a stack
+            // argument which is more complicated to deal with.
+            return;
+          }
+          checkNodes = [node.callee];
+        } else if (node.arguments.length >= 1) {
+          // Handles cases of `.foo(Cu.reportError)`.
+          checkNodes = node.arguments.filter(n => isCuReportError(n));
+        }
+
+        for (let checkNode of checkNodes) {
+          context.report({
+            node,
+            fix: fixer => {
+              let fixes = [
+                fixer.replaceText(checkNode.object, "console"),
+                fixer.replaceText(checkNode.property, "error"),
+              ];
+              // If we're adding stuff together as an argument, split
+              // into multiple arguments instead:
+              if (
+                checkNode == node.callee &&
+                isConcatenation(node.arguments[0])
+              ) {
+                let { fixes: recursiveFixes } = replaceConcatWithComma(
+                  fixer,
+                  node.arguments[0]
+                );
+                fixes.push(...recursiveFixes);
+              }
+              return fixes;
+            },
+            messageId: "useConsoleError",
+          });
+        }
+      },
+    };
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/no-define-cc-etc.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/no-define-cc-etc.js
new file mode 100644
index 0000000000..aeee3170cc
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/no-define-cc-etc.js
@@ -0,0 +1,57 @@
+/**
+ * @fileoverview Reject defining Cc/Ci/Cr/Cu.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+const componentsBlacklist = ["Cc", "Ci", "Cr", "Cu"];
+
+module.exports = {
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/no-define-cc-etc.html",
+    },
+    messages: {
+      noSeparateDefinition:
+        "{{name}} is now defined in global scope, a separate definition is no longer necessary.",
+    },
+    schema: [],
+    type: "suggestion",
+  },
+
+  create(context) {
+    return {
+      VariableDeclarator(node) {
+        if (
+          node.id.type == "Identifier" &&
+          componentsBlacklist.includes(node.id.name)
+        ) {
+          context.report({
+            node,
+            messageId: "noSeparateDefinition",
+            data: { name: node.id.name },
+          });
+        }
+
+        if (node.id.type == "ObjectPattern") {
+          for (let property of node.id.properties) {
+            if (
+              property.type == "Property" &&
+              componentsBlacklist.includes(property.value.name)
+            ) {
+              context.report({
+                node,
+                messageId: "noSeparateDefinition",
+                data: { name: property.value.name },
+              });
+            }
+          }
+        }
+      },
+    };
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/no-redeclare-with-import-autofix.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/no-redeclare-with-import-autofix.js
new file mode 100644
index 0000000000..0eb5b9a3d7
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/no-redeclare-with-import-autofix.js
@@ -0,0 +1,160 @@
+/**
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+const { dirname, join } = require("path");
+
+const eslintBasePath = dirname(require.resolve("eslint"));
+
+const noredeclarePath = join(eslintBasePath, "rules/no-redeclare.js");
+const baseRule = require(noredeclarePath);
+const astUtils = require(join(eslintBasePath, "rules/utils/ast-utils.js"));
+
+// Hack alert: our eslint env is pretty confused about `require` and
+// `loader` for devtools modules - so ignore it for now.
+// See bug 1812547
+const gIgnoredImports = new Set(["loader", "require"]);
+
+/**
+ * Create a trap for a call to `report` that the original rule is
+ * trying to make on `context`.
+ *
+ * Returns a function that forwards to `report` but provides a fixer
+ * for redeclared imports that just removes those imports.
+ *
+ * @return {function}
+ */
+function trapReport(context) {
+  return function (obj) {
+    let declarator = obj.node.parent;
+    while (
+      declarator &&
+      declarator.parent &&
+      declarator.type != "VariableDeclarator"
+    ) {
+      declarator = declarator.parent;
+    }
+    if (
+      declarator &&
+      declarator.type == "VariableDeclarator" &&
+      declarator.id.type == "ObjectPattern" &&
+      declarator.init.type == "CallExpression"
+    ) {
+      let initialization = declarator.init;
+      if (
+        astUtils.isSpecificMemberAccess(
+          initialization.callee,
+          "ChromeUtils",
+          /^import(ESModule|)$/
+        )
+      ) {
+        // Hack alert: our eslint env is pretty confused about `require` and
+        // `loader` for devtools modules - so ignore it for now.
+        // See bug 1812547
+        if (gIgnoredImports.has(obj.node.name)) {
+          return;
+        }
+        // OK, we've got something we can fix. But we should be careful in case
+        // there are multiple imports being destructured.
+        // Do the easy (and common) case first - just one property:
+        if (declarator.id.properties.length == 1) {
+          context.report({
+            node: declarator.parent,
+            messageId: "duplicateImport",
+            data: {
+              name: declarator.id.properties[0].key.name,
+            },
+            fix(fixer) {
+              return fixer.remove(declarator.parent);
+            },
+          });
+          return;
+        }
+
+        // OK, figure out which import is duplicated here:
+        let node = obj.node.parent;
+        // Then remove a comma after it, or a comma before
+        // if there's no comma after it.
+        let sourceCode = context.getSourceCode();
+        let rangeToRemove = node.range;
+        let tokenAfter = sourceCode.getTokenAfter(node);
+        let tokenBefore = sourceCode.getTokenBefore(node);
+        if (astUtils.isCommaToken(tokenAfter)) {
+          rangeToRemove[1] = tokenAfter.range[1];
+        } else if (astUtils.isCommaToken(tokenBefore)) {
+          rangeToRemove[0] = tokenBefore.range[0];
+        }
+        context.report({
+          node,
+          messageId: "duplicateImport",
+          data: {
+            name: node.key.name,
+          },
+          fix(fixer) {
+            return fixer.removeRange(rangeToRemove);
+          },
+        });
+        return;
+      }
+    }
+    if (context.options[0]?.errorForNonImports) {
+      // Report the result from no-redeclare - we can't autofix it.
+      // This can happen for other redeclaration issues, e.g. naming
+      // variables in a way that conflicts with builtins like "URL" or
+      // "escape".
+      context.report(obj);
+    }
+  };
+}
+
+module.exports = {
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/no-redeclare-with-import-autofix.html",
+    },
+    messages: {
+      ...baseRule.meta.messages,
+      duplicateImport:
+        "The import of '{{ name }}' is redundant with one set up earlier (e.g. head.js or the browser window environment). It should be removed.",
+    },
+    schema: [
+      {
+        type: "object",
+        properties: {
+          errorForNonImports: {
+            type: "boolean",
+            default: true,
+          },
+        },
+        additionalProperties: false,
+      },
+    ],
+    type: "suggestion",
+    fixable: "code",
+  },
+
+  create(context) {
+    // Test modules get the browser env applied wrongly in some cases,
+    // don't try and remove imports there. This works out of the box
+    // for sys.mjs modules because eslint won't check builtinGlobals
+    // for the no-redeclare rule.
+    if (context.getFilename().endsWith(".jsm")) {
+      return {};
+    }
+    let newOptions = [{ builtinGlobals: true }];
+    const contextForBaseRule = Object.create(context, {
+      report: {
+        value: trapReport(context),
+        writable: false,
+      },
+      options: {
+        value: newOptions,
+      },
+    });
+    return baseRule.create(contextForBaseRule);
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/no-throw-cr-literal.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/no-throw-cr-literal.js
new file mode 100644
index 0000000000..4b7aeb5151
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/no-throw-cr-literal.js
@@ -0,0 +1,101 @@
+/**
+ * @fileoverview Rule to prevent throwing bare Cr.ERRORs.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+function isCr(object) {
+  return object.type === "Identifier" && object.name === "Cr";
+}
+
+function isComponentsResults(object) {
+  return (
+    object.type === "MemberExpression" &&
+    object.object.type === "Identifier" &&
+    object.object.name === "Components" &&
+    object.property.type === "Identifier" &&
+    object.property.name === "results"
+  );
+}
+
+function isNewError(argument) {
+  return (
+    argument.type === "NewExpression" &&
+    argument.callee.type === "Identifier" &&
+    argument.callee.name === "Error" &&
+    argument.arguments.length === 1
+  );
+}
+
+function fixT(context, node, argument, fixer) {
+  const sourceText = context.getSourceCode().getText(argument);
+  return fixer.replaceText(node, `Components.Exception("", ${sourceText})`);
+}
+
+module.exports = {
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/no-throw-cr-literal.html",
+    },
+    fixable: "code",
+    messages: {
+      bareCR: "Do not throw bare Cr.ERRORs, use Components.Exception instead",
+      bareComponentsResults:
+        "Do not throw bare Components.results.ERRORs, use Components.Exception instead",
+      newErrorCR:
+        "Do not pass Cr.ERRORs to new Error(), use Components.Exception instead",
+      newErrorComponentsResults:
+        "Do not pass Components.results.ERRORs to new Error(), use Components.Exception instead",
+    },
+    schema: [],
+    type: "problem",
+  },
+
+  create(context) {
+    return {
+      ThrowStatement(node) {
+        if (node.argument.type === "MemberExpression") {
+          const fix = fixT.bind(null, context, node.argument, node.argument);
+
+          if (isCr(node.argument.object)) {
+            context.report({
+              node,
+              messageId: "bareCR",
+              fix,
+            });
+          } else if (isComponentsResults(node.argument.object)) {
+            context.report({
+              node,
+              messageId: "bareComponentsResults",
+              fix,
+            });
+          }
+        } else if (isNewError(node.argument)) {
+          const argument = node.argument.arguments[0];
+
+          if (argument.type === "MemberExpression") {
+            const fix = fixT.bind(null, context, node.argument, argument);
+
+            if (isCr(argument.object)) {
+              context.report({
+                node,
+                messageId: "newErrorCR",
+                fix,
+              });
+            } else if (isComponentsResults(argument.object)) {
+              context.report({
+                node,
+                messageId: "newErrorComponentsResults",
+                fix,
+              });
+            }
+          }
+        }
+      },
+    };
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/no-useless-parameters.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/no-useless-parameters.js
new file mode 100644
index 0000000000..cfbbaf601b
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/no-useless-parameters.js
@@ -0,0 +1,156 @@
+/**
+ * @fileoverview Reject common XPCOM methods called with useless optional
+ *               parameters, or non-existent parameters.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+module.exports = {
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/no-useless-parameters.html",
+    },
+    fixable: "code",
+    messages: {
+      newURIParams: "newURI's last parameters are optional.",
+      obmittedWhenFalse:
+        "{{fnName}}'s {{index}} parameter can be omitted when it's false.",
+      onlyTakes: "{{fnName}} only takes {{params}}",
+    },
+    schema: [],
+    type: "suggestion",
+  },
+
+  create(context) {
+    function getRangeAfterArgToEnd(argNumber, args) {
+      let sourceCode = context.getSourceCode();
+      return [
+        sourceCode.getTokenAfter(args[argNumber]).range[0],
+        args[args.length - 1].range[1],
+      ];
+    }
+
+    return {
+      CallExpression(node) {
+        let callee = node.callee;
+        if (
+          callee.type !== "MemberExpression" ||
+          callee.property.type !== "Identifier"
+        ) {
+          return;
+        }
+
+        let isFalse = arg => arg.type === "Literal" && arg.value === false;
+        let isFalsy = arg => arg.type === "Literal" && !arg.value;
+        let isBool = arg =>
+          arg.type === "Literal" && (arg.value === false || arg.value === true);
+        let name = callee.property.name;
+        let args = node.arguments;
+
+        if (
+          ["addEventListener", "removeEventListener", "addObserver"].includes(
+            name
+          ) &&
+          args.length === 3 &&
+          isFalse(args[2])
+        ) {
+          context.report({
+            node,
+            fix: fixer => {
+              return fixer.removeRange(getRangeAfterArgToEnd(1, args));
+            },
+            messageId: "obmittedWhenFalse",
+            data: { fnName: name, index: "third" },
+          });
+        }
+
+        if (name === "clearUserPref" && args.length > 1) {
+          context.report({
+            node,
+            fix: fixer => {
+              return fixer.removeRange(getRangeAfterArgToEnd(0, args));
+            },
+            messageId: "onlyTakes",
+            data: { fnName: name, params: "1 parameter" },
+          });
+        }
+
+        if (name === "removeObserver" && args.length === 3 && isBool(args[2])) {
+          context.report({
+            node,
+            fix: fixer => {
+              return fixer.removeRange(getRangeAfterArgToEnd(1, args));
+            },
+            messageId: "onlyTakes",
+            data: { fnName: name, params: "2 parameters" },
+          });
+        }
+
+        if (name === "appendElement" && args.length === 2 && isFalse(args[1])) {
+          context.report({
+            node,
+            fix: fixer => {
+              return fixer.removeRange(getRangeAfterArgToEnd(0, args));
+            },
+            messageId: "obmittedWhenFalse",
+            data: { fnName: name, index: "second" },
+          });
+        }
+
+        if (
+          name === "notifyObservers" &&
+          args.length === 3 &&
+          isFalsy(args[2])
+        ) {
+          context.report({
+            node,
+            fix: fixer => {
+              return fixer.removeRange(getRangeAfterArgToEnd(1, args));
+            },
+            messageId: "obmittedWhenFalse",
+            data: { fnName: name, index: "third" },
+          });
+        }
+
+        if (
+          name === "getComputedStyle" &&
+          args.length === 2 &&
+          isFalsy(args[1])
+        ) {
+          context.report({
+            node,
+            fix: fixer => {
+              return fixer.removeRange(getRangeAfterArgToEnd(0, args));
+            },
+            messageId: "obmittedWhenFalse",
+            data: { fnName: "getComputedStyle", index: "second" },
+          });
+        }
+
+        if (
+          name === "newURI" &&
+          args.length > 1 &&
+          isFalsy(args[args.length - 1])
+        ) {
+          context.report({
+            node,
+            fix: fixer => {
+              if (args.length > 2 && isFalsy(args[args.length - 2])) {
+                return fixer.removeRange(getRangeAfterArgToEnd(0, args));
+              }
+
+              return fixer.removeRange(
+                getRangeAfterArgToEnd(args.length - 2, args)
+              );
+            },
+            messageId: "newURIParams",
+          });
+        }
+      },
+    };
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/no-useless-removeEventListener.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/no-useless-removeEventListener.js
new file mode 100644
index 0000000000..4915cd16d5
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/no-useless-removeEventListener.js
@@ -0,0 +1,69 @@
+/**
+ * @fileoverview Reject calls to removeEventListenter where {once: true} could
+ *               be used instead.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+module.exports = {
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/no-useless-removeEventListener.html",
+    },
+    messages: {
+      useOnce:
+        "use {once: true} instead of removeEventListener as the first instruction of the listener",
+    },
+    schema: [],
+    type: "suggestion",
+  },
+
+  create(context) {
+    return {
+      CallExpression(node) {
+        let callee = node.callee;
+        if (
+          callee.type !== "MemberExpression" ||
+          callee.property.type !== "Identifier" ||
+          callee.property.name !== "addEventListener" ||
+          node.arguments.length == 4
+        ) {
+          return;
+        }
+
+        let listener = node.arguments[1];
+        if (
+          !listener ||
+          listener.type != "FunctionExpression" ||
+          !listener.body ||
+          listener.body.type != "BlockStatement" ||
+          !listener.body.body.length ||
+          listener.body.body[0].type != "ExpressionStatement" ||
+          listener.body.body[0].expression.type != "CallExpression"
+        ) {
+          return;
+        }
+
+        let call = listener.body.body[0].expression;
+        if (
+          call.callee.type == "MemberExpression" &&
+          call.callee.property.type == "Identifier" &&
+          call.callee.property.name == "removeEventListener" &&
+          ((call.arguments[0].type == "Literal" &&
+            call.arguments[0].value == node.arguments[0].value) ||
+            (call.arguments[0].type == "Identifier" &&
+              call.arguments[0].name == node.arguments[0].name))
+        ) {
+          context.report({
+            node: call,
+            messageId: "useOnce",
+          });
+        }
+      },
+    };
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/no-useless-run-test.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/no-useless-run-test.js
new file mode 100644
index 0000000000..4218f45bbd
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/no-useless-run-test.js
@@ -0,0 +1,76 @@
+/**
+ * @fileoverview Reject run_test() definitions where they aren't necessary.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+module.exports = {
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/no-useless-run-test.html",
+    },
+    fixable: "code",
+    messages: {
+      noUselessRunTest:
+        "Useless run_test function - only contains run_next_test; whole function can be removed",
+    },
+    schema: [],
+    type: "suggestion",
+  },
+
+  create(context) {
+    return {
+      "Program > FunctionDeclaration": function (node) {
+        if (
+          node.id.name === "run_test" &&
+          node.body.type === "BlockStatement" &&
+          node.body.body.length === 1 &&
+          node.body.body[0].type === "ExpressionStatement" &&
+          node.body.body[0].expression.type === "CallExpression" &&
+          node.body.body[0].expression.callee.name === "run_next_test"
+        ) {
+          context.report({
+            node,
+            fix: fixer => {
+              let sourceCode = context.getSourceCode();
+              let startNode;
+              if (sourceCode.getCommentsBefore) {
+                // ESLint 4 has getCommentsBefore.
+                startNode = sourceCode.getCommentsBefore(node);
+              } else if (node && node.body && node.leadingComments) {
+                // This is for ESLint 3.
+                startNode = node.leadingComments;
+              }
+
+              // If we have comments, we want the start node to be the comments,
+              // rather than the token before the comments, so that we don't
+              // remove the comments - for run_test, these are likely to be useful
+              // information about the test.
+              if (startNode?.length) {
+                startNode = startNode[startNode.length - 1];
+              } else {
+                startNode = sourceCode.getTokenBefore(node);
+              }
+
+              return fixer.removeRange([
+                // If there's no startNode, we fall back to zero, i.e. start of
+                // file.
+                startNode ? startNode.range[1] + 1 : 0,
+                // We know the function is a block and it'll end with }. Normally
+                // there's a new line after that, so just advance past it. This
+                // may be slightly not dodgy in some cases, but covers the existing
+                // cases.
+                node.range[1] + 1,
+              ]);
+            },
+            messageId: "noUselessRunTest",
+          });
+        }
+      },
+    };
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/prefer-boolean-length-check.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/prefer-boolean-length-check.js
new file mode 100644
index 0000000000..0e2685ec28
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/prefer-boolean-length-check.js
@@ -0,0 +1,129 @@
+/**
+ * @fileoverview Prefer boolean length check
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+function funcForBooleanLength(context, node, conditionCheck) {
+  let newText = "";
+  const sourceCode = context.getSourceCode();
+  switch (node.operator) {
+    case ">":
+      if (node.right.value == 0) {
+        if (conditionCheck) {
+          newText = sourceCode.getText(node.left);
+        } else {
+          newText = "!!" + sourceCode.getText(node.left);
+        }
+      } else {
+        newText = "!" + sourceCode.getText(node.right);
+      }
+      break;
+    case "<":
+      if (node.right.value == 0) {
+        newText = "!" + sourceCode.getText(node.left);
+      } else if (conditionCheck) {
+        newText = sourceCode.getText(node.right);
+      } else {
+        newText = "!!" + sourceCode.getText(node.right);
+      }
+      break;
+    case "==":
+      if (node.right.value == 0) {
+        newText = "!" + sourceCode.getText(node.left);
+      } else {
+        newText = "!" + sourceCode.getText(node.right);
+      }
+      break;
+    case "!=":
+      if (node.right.value == 0) {
+        if (conditionCheck) {
+          newText = sourceCode.getText(node.left);
+        } else {
+          newText = "!!" + sourceCode.getText(node.left);
+        }
+      } else if (conditionCheck) {
+        newText = sourceCode.getText(node.right);
+      } else {
+        newText = "!!" + sourceCode.getText(node.right);
+      }
+      break;
+  }
+  return newText;
+}
+
+module.exports = {
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/prefer-boolean-length-check.html",
+    },
+    fixable: "code",
+    messages: {
+      preferBooleanCheck: "Prefer boolean length check",
+    },
+    schema: [],
+    type: "suggestion",
+  },
+
+  create(context) {
+    const conditionStatement = [
+      "IfStatement",
+      "WhileStatement",
+      "DoWhileStatement",
+      "ForStatement",
+      "ForInStatement",
+      "ConditionalExpression",
+    ];
+
+    return {
+      BinaryExpression(node) {
+        if (
+          ["==", "!=", ">", "<"].includes(node.operator) &&
+          ((node.right.type == "Literal" &&
+            node.right.value == 0 &&
+            node.left.property?.name == "length") ||
+            (node.left.type == "Literal" &&
+              node.left.value == 0 &&
+              node.right.property?.name == "length"))
+        ) {
+          if (
+            conditionStatement.includes(node.parent.type) ||
+            (node.parent.type == "LogicalExpression" &&
+              conditionStatement.includes(node.parent.parent.type))
+          ) {
+            context.report({
+              node,
+              fix: fixer => {
+                let generateExpression = funcForBooleanLength(
+                  context,
+                  node,
+                  true
+                );
+
+                return fixer.replaceText(node, generateExpression);
+              },
+              messageId: "preferBooleanCheck",
+            });
+          } else {
+            context.report({
+              node,
+              fix: fixer => {
+                let generateExpression = funcForBooleanLength(
+                  context,
+                  node,
+                  false
+                );
+                return fixer.replaceText(node, generateExpression);
+              },
+              messageId: "preferBooleanCheck",
+            });
+          }
+        }
+      },
+    };
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/prefer-formatValues.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/prefer-formatValues.js
new file mode 100644
index 0000000000..29daca3c7c
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/prefer-formatValues.js
@@ -0,0 +1,97 @@
+/**
+ * @fileoverview Reject multiple calls to document.l10n.formatValue in the same
+ * code block.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+function isIdentifier(node, id) {
+  return node && node.type === "Identifier" && node.name === id;
+}
+
+/**
+ * As we enter blocks new sets are pushed onto this stack and then popped when
+ * we exit the block.
+ */
+const BlockStack = [];
+
+module.exports = {
+  meta: {
+    docs: {
+      description: "disallow multiple document.l10n.formatValue calls",
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/prefer-formatValues.html",
+    },
+    messages: {
+      outsideCallBlock: "call expression found outside of known block",
+      useSingleCall:
+        "prefer to use a single document.l10n.formatValues call instead " +
+        "of multiple calls to document.l10n.formatValue or document.l10n.formatValues",
+    },
+    schema: [],
+    type: "problem",
+  },
+
+  create(context) {
+    function enterBlock() {
+      BlockStack.push(new Set());
+    }
+
+    function exitBlock() {
+      let calls = BlockStack.pop();
+      if (calls.size > 1) {
+        for (let callNode of calls) {
+          context.report({
+            node: callNode,
+            messageId: "useSingleCall",
+          });
+        }
+      }
+    }
+
+    return {
+      Program: enterBlock,
+      "Program:exit": exitBlock,
+      BlockStatement: enterBlock,
+      "BlockStatement:exit": exitBlock,
+
+      CallExpression(node) {
+        if (!BlockStack.length) {
+          context.report({
+            node,
+            messageId: "outsideCallBlock",
+          });
+        }
+
+        let callee = node.callee;
+        if (callee.type !== "MemberExpression") {
+          return;
+        }
+
+        if (
+          !isIdentifier(callee.property, "formatValue") &&
+          !isIdentifier(callee.property, "formatValues")
+        ) {
+          return;
+        }
+
+        if (callee.object.type !== "MemberExpression") {
+          return;
+        }
+
+        if (
+          !isIdentifier(callee.object.object, "document") ||
+          !isIdentifier(callee.object.property, "l10n")
+        ) {
+          return;
+        }
+
+        let calls = BlockStack[BlockStack.length - 1];
+        calls.add(node);
+      },
+    };
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/reject-addtask-only.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/reject-addtask-only.js
new file mode 100644
index 0000000000..fa6de2f8b9
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/reject-addtask-only.js
@@ -0,0 +1,48 @@
+/**
+ * @fileoverview Don't allow only() in tests
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+module.exports = {
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/reject-addtask-only.html",
+    },
+    hasSuggestions: true,
+    schema: [],
+    type: "suggestion",
+  },
+
+  create(context) {
+    return {
+      CallExpression(node) {
+        if (
+          ["add_task", "decorate_task"].includes(
+            node.callee.object?.callee?.name
+          ) &&
+          node.callee.property?.name == "only"
+        ) {
+          context.report({
+            node,
+            message: `add_task(...).only() not allowed - add an exception if this is intentional`,
+            suggest: [
+              {
+                desc: "Remove only() call from task",
+                fix: fixer =>
+                  fixer.replaceTextRange(
+                    [node.callee.object.range[1], node.range[1]],
+                    ""
+                  ),
+              },
+            ],
+          });
+        }
+      },
+    };
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/reject-chromeutils-import-params.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/reject-chromeutils-import-params.js
new file mode 100644
index 0000000000..4fbd126b65
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/reject-chromeutils-import-params.js
@@ -0,0 +1,62 @@
+/**
+ * @fileoverview Reject calls to ChromeUtils.import(..., null). This allows to
+ * retrieve the global object for the JSM, instead we should rely on explicitly
+ * exported symbols.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+function isIdentifier(node, id) {
+  return node && node.type === "Identifier" && node.name === id;
+}
+
+function getRangeAfterArgToEnd(context, argNumber, args) {
+  let sourceCode = context.getSourceCode();
+  return [
+    sourceCode.getTokenAfter(args[argNumber]).range[0],
+    args[args.length - 1].range[1],
+  ];
+}
+
+module.exports = {
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/reject-chromeutils-import-params.html",
+    },
+    hasSuggestions: true,
+    schema: [],
+    type: "problem",
+  },
+
+  create(context) {
+    return {
+      CallExpression(node) {
+        let { callee } = node;
+        if (
+          isIdentifier(callee.object, "ChromeUtils") &&
+          isIdentifier(callee.property, "import") &&
+          node.arguments.length >= 2
+        ) {
+          context.report({
+            node,
+            message: "ChromeUtils.import only takes one argument.",
+            suggest: [
+              {
+                desc: "Remove the unnecessary parameters.",
+                fix: fixer => {
+                  return fixer.removeRange(
+                    getRangeAfterArgToEnd(context, 0, node.arguments)
+                  );
+                },
+              },
+            ],
+          });
+        }
+      },
+    };
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/reject-eager-module-in-lazy-getter.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/reject-eager-module-in-lazy-getter.js
new file mode 100644
index 0000000000..df397ad253
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/reject-eager-module-in-lazy-getter.js
@@ -0,0 +1,103 @@
+/**
+ * @fileoverview Reject use of lazy getters for modules that's loaded early in
+ *               the startup process and not necessarily be lazy.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+const helpers = require("../helpers");
+
+function isString(node) {
+  return node.type === "Literal" && typeof node.value === "string";
+}
+
+function isEagerModule(resourceURI) {
+  return [
+    "resource://gre/modules/Services",
+    "resource://gre/modules/XPCOMUtils",
+    "resource://gre/modules/AppConstants",
+  ].includes(resourceURI.replace(/(\.jsm|\.jsm\.js|\.js|\.sys\.mjs)$/, ""));
+}
+
+function checkEagerModule(context, node, resourceURI) {
+  if (!isEagerModule(resourceURI)) {
+    return;
+  }
+  context.report({
+    node,
+    messageId: "eagerModule",
+    data: { uri: resourceURI },
+  });
+}
+
+module.exports = {
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/reject-eager-module-in-lazy-getter.html",
+    },
+    messages: {
+      eagerModule:
+        'Module "{{uri}}" is known to be loaded early in the startup process, and should be loaded eagerly, instead of defining a lazy getter.',
+    },
+    schema: [],
+    type: "problem",
+  },
+
+  create(context) {
+    return {
+      CallExpression(node) {
+        if (node.callee.type !== "MemberExpression") {
+          return;
+        }
+
+        let callerSource;
+        try {
+          callerSource = helpers.getASTSource(node.callee);
+        } catch (e) {
+          return;
+        }
+
+        if (
+          callerSource === "XPCOMUtils.defineLazyModuleGetter" ||
+          callerSource === "ChromeUtils.defineModuleGetter"
+        ) {
+          if (node.arguments.length < 3) {
+            return;
+          }
+          const resourceURINode = node.arguments[2];
+          if (!isString(resourceURINode)) {
+            return;
+          }
+          checkEagerModule(context, node, resourceURINode.value);
+        } else if (
+          callerSource === "XPCOMUtils.defineLazyModuleGetters" ||
+          callerSource === "ChromeUtils.defineESModuleGetters"
+        ) {
+          if (node.arguments.length < 2) {
+            return;
+          }
+          const obj = node.arguments[1];
+          if (obj.type !== "ObjectExpression") {
+            return;
+          }
+          for (let prop of obj.properties) {
+            if (prop.type !== "Property") {
+              continue;
+            }
+            if (prop.kind !== "init") {
+              continue;
+            }
+            const resourceURINode = prop.value;
+            if (!isString(resourceURINode)) {
+              continue;
+            }
+            checkEagerModule(context, node, resourceURINode.value);
+          }
+        }
+      },
+    };
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/reject-global-this.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/reject-global-this.js
new file mode 100644
index 0000000000..61d2b9639a
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/reject-global-this.js
@@ -0,0 +1,40 @@
+/**
+ * @fileoverview Reject attempts to use the global object in jsms.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+const helpers = require("../helpers");
+
+// -----------------------------------------------------------------------------
+// Rule Definition
+// -----------------------------------------------------------------------------
+
+module.exports = {
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/reject-global-this.html",
+    },
+    schema: [],
+    type: "problem",
+  },
+
+  create(context) {
+    return {
+      ThisExpression(node) {
+        if (!helpers.getIsGlobalThis(context.getAncestors())) {
+          return;
+        }
+
+        context.report({
+          node,
+          message: `JSM should not use the global this`,
+        });
+      },
+    };
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/reject-globalThis-modification.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/reject-globalThis-modification.js
new file mode 100644
index 0000000000..4bcf7e3822
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/reject-globalThis-modification.js
@@ -0,0 +1,70 @@
+/**
+ * @fileoverview Enforce the standard object name for
+ * ChromeUtils.defineESMGetters
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+function isIdentifier(node, id) {
+  return node.type === "Identifier" && node.name === id;
+}
+
+function calleeToString(node) {
+  if (node.type === "Identifier") {
+    return node.name;
+  }
+
+  if (node.type === "MemberExpression" && !node.computed) {
+    return calleeToString(node.object) + "." + node.property.name;
+  }
+
+  return "???";
+}
+
+module.exports = {
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/reject-globalThis-modification.html",
+    },
+    schema: [],
+    type: "problem",
+  },
+
+  create(context) {
+    return {
+      AssignmentExpression(node, parents) {
+        let target = node.left;
+        while (target.type === "MemberExpression") {
+          target = target.object;
+        }
+        if (isIdentifier(target, "globalThis")) {
+          context.report({
+            node,
+            message:
+              "`globalThis` shouldn't be modified. `globalThis` is the shared global inside the system module, and properties defined on it is visible from all modules.",
+          });
+        }
+      },
+      CallExpression(node) {
+        const calleeStr = calleeToString(node.callee);
+        if (calleeStr.endsWith(".deserialize")) {
+          return;
+        }
+
+        for (const arg of node.arguments) {
+          if (isIdentifier(arg, "globalThis")) {
+            context.report({
+              node,
+              message:
+                "`globalThis` shouldn't be passed to function that can modify it. `globalThis` is the shared global inside the system module, and properties defined on it is visible from all modules.",
+            });
+          }
+        }
+      },
+    };
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/reject-import-system-module-from-non-system.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/reject-import-system-module-from-non-system.js
new file mode 100644
index 0000000000..9e640a696c
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/reject-import-system-module-from-non-system.js
@@ -0,0 +1,36 @@
+/**
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+module.exports = {
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/reject-import-system-module-from-non-system.html",
+    },
+    messages: {
+      rejectStaticImportSystemModuleFromNonSystem:
+        "System modules (*.sys.mjs) can be imported with static import declaration only from system modules.",
+    },
+    schema: [],
+    type: "problem",
+  },
+
+  create(context) {
+    return {
+      ImportDeclaration(node) {
+        if (!node.source.value.endsWith(".sys.mjs")) {
+          return;
+        }
+
+        context.report({
+          node,
+          messageId: "rejectStaticImportSystemModuleFromNonSystem",
+        });
+      },
+    };
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/reject-importGlobalProperties.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/reject-importGlobalProperties.js
new file mode 100644
index 0000000000..1012c12350
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/reject-importGlobalProperties.js
@@ -0,0 +1,94 @@
+/**
+ * @fileoverview Reject use of Cu.importGlobalProperties
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+const path = require("path");
+
+const privilegedGlobals = Object.keys(
+  require("../environments/privileged.js").globals
+);
+
+module.exports = {
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/reject-importGlobalProperties.html",
+    },
+    messages: {
+      unexpectedCall: "Unexpected call to Cu.importGlobalProperties",
+      unexpectedCallCuWebIdl:
+        "Unnecessary call to Cu.importGlobalProperties for {{name}} (webidl names are automatically imported)",
+      unexpectedCallXPCOMWebIdl:
+        "Unnecessary call to XPCOMUtils.defineLazyGlobalGetters for {{name}} (webidl names are automatically imported)",
+    },
+    schema: [
+      {
+        enum: ["everything", "allownonwebidl"],
+      },
+    ],
+    type: "problem",
+  },
+
+  create(context) {
+    return {
+      CallExpression(node) {
+        if (
+          node.callee.type !== "MemberExpression" ||
+          // TODO Bug 1501127: sjs files have their own sandbox, and do not inherit
+          // the Window backstage pass directly.
+          path.extname(context.getFilename()) == ".sjs"
+        ) {
+          return;
+        }
+        let memexp = node.callee;
+        if (
+          memexp.object.type === "Identifier" &&
+          // Only Cu, not Components.utils as `use-cc-etc` handles this for us.
+          memexp.object.name === "Cu" &&
+          memexp.property.type === "Identifier" &&
+          memexp.property.name === "importGlobalProperties"
+        ) {
+          if (context.options.includes("allownonwebidl")) {
+            for (let element of node.arguments[0].elements) {
+              if (privilegedGlobals.includes(element.value)) {
+                context.report({
+                  node,
+                  messageId: "unexpectedCallCuWebIdl",
+                  data: { name: element.value },
+                });
+              }
+            }
+          } else {
+            context.report({ node, messageId: "unexpectedCall" });
+          }
+        }
+        if (
+          memexp.object.type === "Identifier" &&
+          memexp.object.name === "XPCOMUtils" &&
+          memexp.property.type === "Identifier" &&
+          memexp.property.name === "defineLazyGlobalGetters" &&
+          node.arguments.length >= 2
+        ) {
+          if (context.options.includes("allownonwebidl")) {
+            for (let element of node.arguments[1].elements) {
+              if (privilegedGlobals.includes(element.value)) {
+                context.report({
+                  node,
+                  messageId: "unexpectedCallXPCOMWebIdl",
+                  data: { name: element.value },
+                });
+              }
+            }
+          } else {
+            context.report({ node, messageId: "unexpectedCall" });
+          }
+        }
+      },
+    };
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/reject-lazy-imports-into-globals.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/reject-lazy-imports-into-globals.js
new file mode 100644
index 0000000000..433db12e08
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/reject-lazy-imports-into-globals.js
@@ -0,0 +1,76 @@
+/**
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+const helpers = require("../helpers");
+
+const callExpressionDefinitions = [
+  /^loader\.lazyGetter\((?:globalThis|window), "(\w+)"/,
+  /^loader\.lazyServiceGetter\((?:globalThis|window), "(\w+)"/,
+  /^loader\.lazyRequireGetter\((?:globalThis|window), "(\w+)"/,
+  /^XPCOMUtils\.defineLazyGetter\((?:globalThis|window), "(\w+)"/,
+  /^XPCOMUtils\.defineLazyModuleGetter\((?:globalThis|window), "(\w+)"/,
+  /^ChromeUtils\.defineLazyGetter\((?:globalThis|window), "(\w+)"/,
+  /^ChromeUtils\.defineModuleGetter\((?:globalThis|window), "(\w+)"/,
+  /^XPCOMUtils\.defineLazyPreferenceGetter\((?:globalThis|window), "(\w+)"/,
+  /^XPCOMUtils\.defineLazyProxy\((?:globalThis|window), "(\w+)"/,
+  /^XPCOMUtils\.defineLazyScriptGetter\((?:globalThis|window), "(\w+)"/,
+  /^XPCOMUtils\.defineLazyServiceGetter\((?:globalThis|window), "(\w+)"/,
+  /^XPCOMUtils\.defineConstant\((?:globalThis|window), "(\w+)"/,
+  /^DevToolsUtils\.defineLazyModuleGetter\((?:globalThis|window), "(\w+)"/,
+  /^DevToolsUtils\.defineLazyGetter\((?:globalThis|window), "(\w+)"/,
+  /^Object\.defineProperty\((?:globalThis|window), "(\w+)"/,
+  /^Reflect\.defineProperty\((?:globalThis|window), "(\w+)"/,
+  /^this\.__defineGetter__\("(\w+)"/,
+];
+
+const callExpressionMultiDefinitions = [
+  "XPCOMUtils.defineLazyGlobalGetters(window,",
+  "XPCOMUtils.defineLazyGlobalGetters(globalThis,",
+  "XPCOMUtils.defineLazyModuleGetters(window,",
+  "XPCOMUtils.defineLazyModuleGetters(globalThis,",
+  "XPCOMUtils.defineLazyServiceGetters(window,",
+  "XPCOMUtils.defineLazyServiceGetters(globalThis,",
+  "ChromeUtils.defineESModuleGetters(window,",
+  "ChromeUtils.defineESModuleGetters(globalThis,",
+  "loader.lazyRequireGetter(window,",
+  "loader.lazyRequireGetter(globalThis,",
+];
+
+module.exports = {
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/reject-lazy-imports-into-globals.html",
+    },
+    messages: {
+      rejectLazyImportsIntoGlobals:
+        "Non-system modules should not import into globalThis nor window. Prefer a lazy object holder",
+    },
+    schema: [],
+    type: "suggestion",
+  },
+
+  create(context) {
+    return {
+      CallExpression(node) {
+        let source;
+        try {
+          source = helpers.getASTSource(node);
+        } catch (e) {
+          return;
+        }
+
+        if (
+          callExpressionDefinitions.some(expr => source.match(expr)) ||
+          callExpressionMultiDefinitions.some(expr => source.startsWith(expr))
+        ) {
+          context.report({ node, messageId: "rejectLazyImportsIntoGlobals" });
+        }
+      },
+    };
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/reject-mixing-eager-and-lazy.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/reject-mixing-eager-and-lazy.js
new file mode 100644
index 0000000000..39cb4b5fc3
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/reject-mixing-eager-and-lazy.js
@@ -0,0 +1,153 @@
+/**
+ * @fileoverview Reject use of lazy getters for modules that's loaded early in
+ *               the startup process and not necessarily be lazy.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+const helpers = require("../helpers");
+
+function isIdentifier(node, id) {
+  return node.type === "Identifier" && node.name === id;
+}
+
+function isString(node) {
+  return node.type === "Literal" && typeof node.value === "string";
+}
+
+function checkMixed(loadedModules, context, node, type, resourceURI) {
+  if (!loadedModules.has(resourceURI)) {
+    loadedModules.set(resourceURI, type);
+  }
+
+  if (loadedModules.get(resourceURI) === type) {
+    return;
+  }
+
+  context.report({
+    node,
+    messageId: "mixedEagerAndLazy",
+    data: { uri: resourceURI },
+  });
+}
+
+module.exports = {
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/reject-mixed-eager-and-lazy.html",
+    },
+    messages: {
+      mixedEagerAndLazy:
+        'Module "{{uri}}" is loaded eagerly, and should not be used for lazy getter.',
+    },
+    schema: [],
+    type: "problem",
+  },
+
+  create(context) {
+    const loadedModules = new Map();
+
+    return {
+      ImportDeclaration(node) {
+        const resourceURI = node.source.value;
+        checkMixed(loadedModules, context, node, "eager", resourceURI);
+      },
+      CallExpression(node) {
+        if (node.callee.type !== "MemberExpression") {
+          return;
+        }
+
+        let callerSource;
+        try {
+          callerSource = helpers.getASTSource(node.callee);
+        } catch (e) {
+          return;
+        }
+
+        if (
+          (callerSource === "ChromeUtils.import" ||
+            callerSource === "ChromeUtils.importESModule") &&
+          helpers.getIsTopLevelAndUnconditionallyExecuted(
+            context.getAncestors()
+          )
+        ) {
+          if (node.arguments.length < 1) {
+            return;
+          }
+          const resourceURINode = node.arguments[0];
+          if (!isString(resourceURINode)) {
+            return;
+          }
+          checkMixed(
+            loadedModules,
+            context,
+            node,
+            "eager",
+            resourceURINode.value
+          );
+        }
+
+        if (
+          callerSource === "XPCOMUtils.defineLazyModuleGetter" ||
+          callerSource === "ChromeUtils.defineModuleGetter"
+        ) {
+          if (node.arguments.length < 3) {
+            return;
+          }
+          if (!isIdentifier(node.arguments[0], "lazy")) {
+            return;
+          }
+
+          const resourceURINode = node.arguments[2];
+          if (!isString(resourceURINode)) {
+            return;
+          }
+          checkMixed(
+            loadedModules,
+            context,
+            node,
+            "lazy",
+            resourceURINode.value
+          );
+        } else if (
+          callerSource === "XPCOMUtils.defineLazyModuleGetters" ||
+          callerSource === "ChromeUtils.defineESModuleGetters"
+        ) {
+          if (node.arguments.length < 2) {
+            return;
+          }
+          if (!isIdentifier(node.arguments[0], "lazy")) {
+            return;
+          }
+
+          const obj = node.arguments[1];
+          if (obj.type !== "ObjectExpression") {
+            return;
+          }
+          for (let prop of obj.properties) {
+            if (prop.type !== "Property") {
+              continue;
+            }
+            if (prop.kind !== "init") {
+              continue;
+            }
+            const resourceURINode = prop.value;
+            if (!isString(resourceURINode)) {
+              continue;
+            }
+            checkMixed(
+              loadedModules,
+              context,
+              node,
+              "lazy",
+              resourceURINode.value
+            );
+          }
+        }
+      },
+    };
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/reject-multiple-getters-calls.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/reject-multiple-getters-calls.js
new file mode 100644
index 0000000000..73d60f3485
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/reject-multiple-getters-calls.js
@@ -0,0 +1,81 @@
+/**
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+const helpers = require("../helpers");
+
+function findStatement(node) {
+  while (node && node.type !== "ExpressionStatement") {
+    node = node.parent;
+  }
+
+  return node;
+}
+
+function isIdentifier(node, id) {
+  return node && node.type === "Identifier" && node.name === id;
+}
+
+module.exports = {
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/reject-multiple-getters-calls.html",
+    },
+    messages: {
+      rejectMultipleCalls:
+        "ChromeUtils.defineESModuleGetters is already called for {{target}} in the same context. Please merge those calls",
+    },
+    schema: [],
+    type: "suggestion",
+  },
+
+  create(context) {
+    const parentToTargets = new Map();
+
+    return {
+      CallExpression(node) {
+        let callee = node.callee;
+        if (
+          callee.type === "MemberExpression" &&
+          isIdentifier(callee.object, "ChromeUtils") &&
+          isIdentifier(callee.property, "defineESModuleGetters")
+        ) {
+          const stmt = findStatement(node);
+          if (!stmt) {
+            return;
+          }
+
+          let target;
+          try {
+            target = helpers.getASTSource(node.arguments[0]);
+          } catch (e) {
+            return;
+          }
+
+          const parent = stmt.parent;
+          let targets;
+          if (parentToTargets.has(parent)) {
+            targets = parentToTargets.get(parent);
+          } else {
+            targets = new Set();
+            parentToTargets.set(parent, targets);
+          }
+
+          if (targets.has(target)) {
+            context.report({
+              node,
+              messageId: "rejectMultipleCalls",
+              data: { target },
+            });
+          }
+
+          targets.add(target);
+        }
+      },
+    };
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/reject-relative-requires.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/reject-relative-requires.js
new file mode 100644
index 0000000000..3231656941
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/reject-relative-requires.js
@@ -0,0 +1,39 @@
+/**
+ * @fileoverview Reject some uses of require.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+var helpers = require("../helpers");
+
+const isRelativePath = function (path) {
+  return path.startsWith("./") || path.startsWith("../");
+};
+
+module.exports = {
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/reject-relative-requires.html",
+    },
+    schema: [],
+    type: "problem",
+  },
+
+  create(context) {
+    return {
+      CallExpression(node) {
+        const path = helpers.getDevToolsRequirePath(node);
+        if (path && isRelativePath(path)) {
+          context.report({
+            node,
+            message: "relative paths are not allowed with require()",
+          });
+        }
+      },
+    };
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/reject-scriptableunicodeconverter.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/reject-scriptableunicodeconverter.js
new file mode 100644
index 0000000000..03474d8838
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/reject-scriptableunicodeconverter.js
@@ -0,0 +1,41 @@
+/**
+ * @fileoverview Reject calls into Ci.nsIScriptableUnicodeConverter. We're phasing this out in
+ * favour of TextEncoder or TextDecoder.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+function isIdentifier(node, id) {
+  return node && node.type === "Identifier" && node.name === id;
+}
+
+module.exports = {
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/reject-scriptableunicodeconverter.html",
+    },
+    schema: [],
+    type: "problem",
+  },
+
+  create(context) {
+    return {
+      MemberExpression(node) {
+        if (
+          isIdentifier(node.object, "Ci") &&
+          isIdentifier(node.property, "nsIScriptableUnicodeConverter")
+        ) {
+          context.report({
+            node,
+            message:
+              "Ci.nsIScriptableUnicodeConverter is deprecated. You should use TextEncoder or TextDecoder instead.",
+          });
+        }
+      },
+    };
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/reject-some-requires.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/reject-some-requires.js
new file mode 100644
index 0000000000..9495b0ff11
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/reject-some-requires.js
@@ -0,0 +1,41 @@
+/**
+ * @fileoverview Reject some uses of require.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+var helpers = require("../helpers");
+
+module.exports = {
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/reject-some-requires.html",
+    },
+    schema: [
+      {
+        type: "string",
+      },
+    ],
+    type: "problem",
+  },
+
+  create(context) {
+    if (typeof context.options[0] !== "string") {
+      throw new Error("reject-some-requires expects a regexp");
+    }
+    const RX = new RegExp(context.options[0]);
+
+    return {
+      CallExpression(node) {
+        const path = helpers.getDevToolsRequirePath(node);
+        if (path && RX.test(path)) {
+          context.report({ node, message: `require(${path}) is not allowed` });
+        }
+      },
+    };
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/reject-top-level-await.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/reject-top-level-await.js
new file mode 100644
index 0000000000..023a62b9fc
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/reject-top-level-await.js
@@ -0,0 +1,45 @@
+/**
+ * @fileoverview Don't allow only() in tests
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+var helpers = require("../helpers");
+
+module.exports = {
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/reject-top-level-await.html",
+    },
+    messages: {
+      rejectTopLevelAwait:
+        "Top-level await is not currently supported in component files.",
+    },
+    schema: [],
+    type: "problem",
+  },
+
+  create(context) {
+    return {
+      AwaitExpression(node) {
+        if (!helpers.getIsTopLevelScript(context.getAncestors())) {
+          return;
+        }
+        context.report({ node, messageId: "rejectTopLevelAwait" });
+      },
+      ForOfStatement(node) {
+        if (
+          !node.await ||
+          !helpers.getIsTopLevelScript(context.getAncestors())
+        ) {
+          return;
+        }
+        context.report({ node, messageId: "rejectTopLevelAwait" });
+      },
+    };
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/rejects-requires-await.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/rejects-requires-await.js
new file mode 100644
index 0000000000..b806e6154d
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/rejects-requires-await.js
@@ -0,0 +1,47 @@
+/**
+ * @fileoverview Ensure Assert.rejects is preceded by await.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+module.exports = {
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/reject-requires-await.html",
+    },
+    messages: {
+      rejectRequiresAwait: "Assert.rejects needs to be preceded by await.",
+    },
+    schema: [],
+    type: "problem",
+  },
+
+  create(context) {
+    return {
+      CallExpression(node) {
+        if (node.callee.type === "MemberExpression") {
+          let memexp = node.callee;
+          if (
+            memexp.object.type === "Identifier" &&
+            memexp.object.name === "Assert" &&
+            memexp.property.type === "Identifier" &&
+            memexp.property.name === "rejects"
+          ) {
+            // We have ourselves an Assert.rejects.
+
+            if (node.parent.type !== "AwaitExpression") {
+              context.report({
+                node,
+                messageId: "rejectRequiresAwait",
+              });
+            }
+          }
+        }
+      },
+    };
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/use-cc-etc.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/use-cc-etc.js
new file mode 100644
index 0000000000..fe2e0b518d
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/use-cc-etc.js
@@ -0,0 +1,52 @@
+/**
+ * @fileoverview Reject use of Components.classes etc, prefer the shorthand instead.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+const componentsMap = {
+  classes: "Cc",
+  interfaces: "Ci",
+  results: "Cr",
+  utils: "Cu",
+};
+
+module.exports = {
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/use-cc-etc.html",
+    },
+    fixable: "code",
+    schema: [],
+    type: "suggestion",
+  },
+
+  create(context) {
+    return {
+      MemberExpression(node) {
+        if (
+          node.object.type === "Identifier" &&
+          node.object.name === "Components" &&
+          node.property.type === "Identifier" &&
+          Object.getOwnPropertyNames(componentsMap).includes(node.property.name)
+        ) {
+          context.report({
+            node,
+            message: `Use ${
+              componentsMap[node.property.name]
+            } rather than Components.${node.property.name}`,
+            fix: fixer =>
+              fixer.replaceTextRange(
+                [node.range[0], node.range[1]],
+                componentsMap[node.property.name]
+              ),
+          });
+        }
+      },
+    };
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/use-chromeutils-generateqi.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/use-chromeutils-generateqi.js
new file mode 100644
index 0000000000..5b8b58855d
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/use-chromeutils-generateqi.js
@@ -0,0 +1,105 @@
+/**
+ * @fileoverview Reject use of XPCOMUtils.generateQI and JS-implemented
+ *               QueryInterface methods in favor of ChromeUtils.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+function isIdentifier(node, id) {
+  return node && node.type === "Identifier" && node.name === id;
+}
+
+function isMemberExpression(node, object, member) {
+  return (
+    node.type === "MemberExpression" &&
+    isIdentifier(node.object, object) &&
+    isIdentifier(node.property, member)
+  );
+}
+
+const MSG_NO_JS_QUERY_INTERFACE =
+  "Please use ChromeUtils.generateQI rather than manually creating " +
+  "JavaScript QueryInterface functions";
+
+const MSG_NO_XPCOMUTILS_GENERATEQI =
+  "Please use ChromeUtils.generateQI instead of XPCOMUtils.generateQI";
+
+function funcToGenerateQI(context, node) {
+  const sourceCode = context.getSourceCode();
+  const text = sourceCode.getText(node);
+
+  let interfaces = [];
+  let match;
+  let re = /\bCi\.([a-zA-Z0-9]+)\b|\b(nsI[A-Z][a-zA-Z0-9]+)\b/g;
+  while ((match = re.exec(text))) {
+    interfaces.push(match[1] || match[2]);
+  }
+
+  let ifaces = interfaces
+    .filter(iface => iface != "nsISupports")
+    .map(iface => JSON.stringify(iface))
+    .join(", ");
+
+  return `ChromeUtils.generateQI([${ifaces}])`;
+}
+
+module.exports = {
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/use-chromeutils-generateqi.html",
+    },
+    fixable: "code",
+    schema: [],
+    type: "suggestion",
+  },
+
+  create(context) {
+    return {
+      CallExpression(node) {
+        let { callee } = node;
+        if (isMemberExpression(callee, "XPCOMUtils", "generateQI")) {
+          context.report({
+            node,
+            message: MSG_NO_XPCOMUTILS_GENERATEQI,
+            fix(fixer) {
+              return fixer.replaceText(callee, "ChromeUtils.generateQI");
+            },
+          });
+        }
+      },
+
+      "AssignmentExpression > MemberExpression[property.name='QueryInterface']":
+        function (node) {
+          const { right } = node.parent;
+          if (right.type === "FunctionExpression") {
+            context.report({
+              node: node.parent,
+              message: MSG_NO_JS_QUERY_INTERFACE,
+              fix(fixer) {
+                return fixer.replaceText(
+                  right,
+                  funcToGenerateQI(context, right)
+                );
+              },
+            });
+          }
+        },
+
+      "Property[key.name='QueryInterface'][value.type='FunctionExpression']":
+        function (node) {
+          context.report({
+            node,
+            message: MSG_NO_JS_QUERY_INTERFACE,
+            fix(fixer) {
+              let generateQI = funcToGenerateQI(context, node.value);
+              return fixer.replaceText(node, `QueryInterface: ${generateQI}`);
+            },
+          });
+        },
+    };
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/use-chromeutils-import.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/use-chromeutils-import.js
new file mode 100644
index 0000000000..90877bed11
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/use-chromeutils-import.js
@@ -0,0 +1,78 @@
+/**
+ * @fileoverview Reject use of Cu.import and XPCOMUtils.defineLazyModuleGetter
+ *               in favor of ChromeUtils.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+function isIdentifier(node, id) {
+  return node && node.type === "Identifier" && node.name === id;
+}
+
+function isMemberExpression(node, object, member) {
+  return (
+    node.type === "MemberExpression" &&
+    isIdentifier(node.object, object) &&
+    isIdentifier(node.property, member)
+  );
+}
+
+module.exports = {
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/use-chromeutils-import.html",
+    },
+    fixable: "code",
+    schema: [],
+    type: "suggestion",
+  },
+
+  create(context) {
+    return {
+      CallExpression(node) {
+        if (node.callee.type !== "MemberExpression") {
+          return;
+        }
+
+        let { callee } = node;
+
+        // Is the expression starting with `Cu` or `Components.utils`?
+        if (
+          (isIdentifier(callee.object, "Cu") ||
+            isMemberExpression(callee.object, "Components", "utils")) &&
+          isIdentifier(callee.property, "import")
+        ) {
+          context.report({
+            node,
+            message: "Please use ChromeUtils.import instead of Cu.import",
+            fix(fixer) {
+              return fixer.replaceText(callee, "ChromeUtils.import");
+            },
+          });
+        }
+
+        if (
+          isMemberExpression(callee, "XPCOMUtils", "defineLazyModuleGetter") &&
+          node.arguments.length < 4
+        ) {
+          context.report({
+            node,
+            message:
+              "Please use ChromeUtils.defineModuleGetter instead of " +
+              "XPCOMUtils.defineLazyModuleGetter",
+            fix(fixer) {
+              return fixer.replaceText(
+                callee,
+                "ChromeUtils.defineModuleGetter"
+              );
+            },
+          });
+        }
+      },
+    };
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/use-default-preference-values.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/use-default-preference-values.js
new file mode 100644
index 0000000000..87fc07057d
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/use-default-preference-values.js
@@ -0,0 +1,52 @@
+/**
+ * @fileoverview Require providing a second parameter to get*Pref
+ * methods instead of using a try/catch block.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+module.exports = {
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/use-default-preference-values.html",
+    },
+    schema: [],
+    type: "suggestion",
+  },
+
+  create(context) {
+    return {
+      TryStatement(node) {
+        let types = ["Bool", "Char", "Float", "Int"];
+        let methods = types.map(type => "get" + type + "Pref");
+        if (
+          node.block.type != "BlockStatement" ||
+          node.block.body.length != 1
+        ) {
+          return;
+        }
+
+        let firstStm = node.block.body[0];
+        if (
+          firstStm.type != "ExpressionStatement" ||
+          firstStm.expression.type != "AssignmentExpression" ||
+          firstStm.expression.right.type != "CallExpression" ||
+          firstStm.expression.right.callee.type != "MemberExpression" ||
+          firstStm.expression.right.callee.property.type != "Identifier" ||
+          !methods.includes(firstStm.expression.right.callee.property.name)
+        ) {
+          return;
+        }
+
+        context.report({
+          node,
+          message: "provide a default value instead of using a try/catch block",
+        });
+      },
+    };
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/use-includes-instead-of-indexOf.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/use-includes-instead-of-indexOf.js
new file mode 100644
index 0000000000..99a04bbb72
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/use-includes-instead-of-indexOf.js
@@ -0,0 +1,50 @@
+/**
+ * @fileoverview Use .includes instead of .indexOf
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+module.exports = {
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/use-includes-instead-of-indexOf.html",
+    },
+    schema: [],
+    type: "suggestion",
+  },
+
+  create(context) {
+    return {
+      BinaryExpression(node) {
+        if (
+          node.left.type != "CallExpression" ||
+          node.left.callee.type != "MemberExpression" ||
+          node.left.callee.property.type != "Identifier" ||
+          node.left.callee.property.name != "indexOf"
+        ) {
+          return;
+        }
+
+        if (
+          (["!=", "!==", "==", "==="].includes(node.operator) &&
+            node.right.type == "UnaryExpression" &&
+            node.right.operator == "-" &&
+            node.right.argument.type == "Literal" &&
+            node.right.argument.value == 1) ||
+          ([">=", "<"].includes(node.operator) &&
+            node.right.type == "Literal" &&
+            node.right.value == 0)
+        ) {
+          context.report({
+            node,
+            message: "use .includes instead of .indexOf",
+          });
+        }
+      },
+    };
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/use-isInstance.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/use-isInstance.js
new file mode 100644
index 0000000000..5f8a8342fc
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/use-isInstance.js
@@ -0,0 +1,154 @@
+/**
+ * @fileoverview Reject use of instanceof against DOM interfaces
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+const fs = require("fs");
+
+const { maybeGetMemberPropertyName } = require("../helpers");
+
+const privilegedGlobals = Object.keys(
+  require("../environments/privileged.js").globals
+);
+
+// -----------------------------------------------------------------------------
+// Rule Definition
+// -----------------------------------------------------------------------------
+
+/**
+ * Whether an identifier is defined by eslint configuration.
+ * `env: { browser: true }` or `globals: []` for example.
+ * @param {import("eslint-scope").Scope} currentScope
+ * @param {import("estree").Identifier} id
+ */
+function refersToEnvironmentGlobals(currentScope, id) {
+  const reference = currentScope.references.find(ref => ref.identifier === id);
+  const { resolved } = reference || {};
+  if (!resolved) {
+    return false;
+  }
+
+  // No definition in script files; defined via .eslintrc
+  return resolved.scope.type === "global" && resolved.defs.length === 0;
+}
+
+/**
+ * Whether a node points to a DOM interface.
+ * Includes direct references to interfaces objects and also indirect references
+ * via property access.
+ * OS.File and lazy.(Foo) are explicitly excluded.
+ *
+ * @example HTMLElement
+ * @example win.HTMLElement
+ * @example iframe.contentWindow.HTMLElement
+ * @example foo.HTMLElement
+ *
+ * @param {import("eslint-scope").Scope} currentScope
+ * @param {import("estree").Node} node
+ */
+function pointsToDOMInterface(currentScope, node) {
+  if (node.type === "MemberExpression") {
+    const objectName = maybeGetMemberPropertyName(node.object);
+    if (objectName === "lazy") {
+      // lazy.Foo is probably a non-IDL import.
+      return false;
+    }
+    if (objectName === "OS" && node.property.name === "File") {
+      // OS.File is an exception that is not a Web IDL interface
+      return false;
+    }
+    // For `win.Foo`, `iframe.contentWindow.Foo`, or such.
+    return privilegedGlobals.includes(node.property.name);
+  }
+
+  if (
+    node.type === "Identifier" &&
+    refersToEnvironmentGlobals(currentScope, node)
+  ) {
+    return privilegedGlobals.includes(node.name);
+  }
+
+  return false;
+}
+
+/**
+ * @param {import("eslint").Rule.RuleContext} context
+ */
+function isChromeContext(context) {
+  const filename = context.getFilename();
+  const isChromeFileName =
+    filename.endsWith(".sys.mjs") ||
+    filename.endsWith(".jsm") ||
+    filename.endsWith(".jsm.js");
+  if (isChromeFileName) {
+    return true;
+  }
+
+  if (filename.endsWith(".xhtml")) {
+    // Treat scripts in XUL files as chrome scripts
+    // Note: readFile is needed as getSourceCode() only gives JS blocks
+    return fs.readFileSync(filename).includes("there.is.only.xul");
+  }
+
+  // Treat scripts as chrome privileged when using:
+  // 1. ChromeUtils, but not SpecialPowers.ChromeUtils
+  // 2. BrowserTestUtils, PlacesUtils
+  // 3. document.createXULElement
+  // 4. loader.lazyRequireGetter
+  // 5. Services.foo, but not SpecialPowers.Services.foo
+  // 6. evalInSandbox
+  const source = context.getSourceCode().text;
+  return !!source.match(
+    /(^|\s)ChromeUtils|BrowserTestUtils|PlacesUtils|createXULElement|lazyRequireGetter|(^|\s)Services\.|evalInSandbox/
+  );
+}
+
+module.exports = {
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/use-isInstance.html",
+    },
+    fixable: "code",
+    schema: [],
+    type: "problem",
+  },
+  /**
+   * @param {import("eslint").Rule.RuleContext} context
+   */
+  create(context) {
+    if (!isChromeContext(context)) {
+      return {};
+    }
+
+    return {
+      BinaryExpression(node) {
+        const { operator, right } = node;
+        if (
+          operator === "instanceof" &&
+          pointsToDOMInterface(context.getScope(), right)
+        ) {
+          context.report({
+            node,
+            message:
+              "Please prefer .isInstance() in chrome scripts over the standard instanceof operator for DOM interfaces, " +
+              "since the latter will return false when the object is created from a different context.",
+            fix(fixer) {
+              const sourceCode = context.getSourceCode();
+              return fixer.replaceText(
+                node,
+                `${sourceCode.getText(right)}.isInstance(${sourceCode.getText(
+                  node.left
+                )})`
+              );
+            },
+          });
+        }
+      },
+    };
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/use-ownerGlobal.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/use-ownerGlobal.js
new file mode 100644
index 0000000000..a61440f579
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/use-ownerGlobal.js
@@ -0,0 +1,40 @@
+/**
+ * @fileoverview Require .ownerGlobal instead of .ownerDocument.defaultView.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+module.exports = {
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/use-ownerGlobal.html",
+    },
+    schema: [],
+    type: "suggestion",
+  },
+
+  create(context) {
+    return {
+      MemberExpression(node) {
+        if (
+          node.property.type != "Identifier" ||
+          node.property.name != "defaultView" ||
+          node.object.type != "MemberExpression" ||
+          node.object.property.type != "Identifier" ||
+          node.object.property.name != "ownerDocument"
+        ) {
+          return;
+        }
+
+        context.report({
+          node,
+          message: "use .ownerGlobal instead of .ownerDocument.defaultView",
+        });
+      },
+    };
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/use-returnValue.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/use-returnValue.js
new file mode 100644
index 0000000000..29722a4f49
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/use-returnValue.js
@@ -0,0 +1,41 @@
+/**
+ * @fileoverview Warn when idempotent methods are called and their return value is unused.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+module.exports = {
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/use-returnValue.html",
+    },
+    schema: [],
+    type: "problem",
+  },
+
+  create(context) {
+    return {
+      ExpressionStatement(node) {
+        if (
+          node.expression?.type != "CallExpression" ||
+          node.expression.callee?.type != "MemberExpression" ||
+          node.expression.callee.property?.type != "Identifier" ||
+          !["concat", "join", "slice"].includes(
+            node.expression.callee.property?.name
+          )
+        ) {
+          return;
+        }
+
+        context.report({
+          node,
+          message: `{Array/String}.${node.expression.callee.property.name} doesn't modify the instance in-place`,
+        });
+      },
+    };
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/use-services.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/use-services.js
new file mode 100644
index 0000000000..75118d59e8
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/use-services.js
@@ -0,0 +1,104 @@
+/**
+ * @fileoverview Require use of Services.* rather than getService.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+const helpers = require("../helpers");
+
+let servicesInterfaceMap = helpers.servicesData;
+
+module.exports = {
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/use-services.html",
+    },
+    // fixable: "code",
+    schema: [],
+    type: "suggestion",
+  },
+
+  create(context) {
+    return {
+      CallExpression(node) {
+        if (!node.callee || !node.callee.property) {
+          return;
+        }
+
+        if (
+          node.callee.property.type == "Identifier" &&
+          node.callee.property.name == "defineLazyServiceGetter" &&
+          node.arguments.length == 4 &&
+          node.arguments[3].type == "Literal" &&
+          node.arguments[3].value in servicesInterfaceMap
+        ) {
+          let serviceName = servicesInterfaceMap[node.arguments[3].value];
+
+          context.report({
+            node,
+            message: `Use Services.${serviceName} rather than defineLazyServiceGetter.`,
+          });
+          return;
+        }
+
+        if (
+          node.callee.property.type == "Identifier" &&
+          node.callee.property.name == "defineLazyServiceGetters" &&
+          node.arguments.length == 2 &&
+          node.arguments[1].type == "ObjectExpression"
+        ) {
+          for (let property of node.arguments[1].properties) {
+            if (
+              property.value.type == "ArrayExpression" &&
+              property.value.elements.length == 2 &&
+              property.value.elements[1].value in servicesInterfaceMap
+            ) {
+              let serviceName =
+                servicesInterfaceMap[property.value.elements[1].value];
+
+              context.report({
+                node: property.value,
+                message: `Use Services.${serviceName} rather than defineLazyServiceGetters.`,
+              });
+            }
+          }
+          return;
+        }
+
+        if (
+          node.callee.property.type != "Identifier" ||
+          node.callee.property.name != "getService" ||
+          node.arguments.length != 1 ||
+          !node.arguments[0].property ||
+          node.arguments[0].property.type != "Identifier" ||
+          !node.arguments[0].property.name ||
+          !(node.arguments[0].property.name in servicesInterfaceMap)
+        ) {
+          return;
+        }
+
+        let serviceName = servicesInterfaceMap[node.arguments[0].property.name];
+        context.report({
+          node,
+          message: `Use Services.${serviceName} rather than getService().`,
+          // This is not enabled by default as for mochitest plain tests we
+          // would need to replace with `SpecialPowers.Services.${serviceName}`.
+          // At the moment we do not have an easy way to detect that.
+          // fix(fixer) {
+          //   let sourceCode = context.getSourceCode();
+          //   return fixer.replaceTextRange(
+          //     [
+          //       sourceCode.getFirstToken(node.callee).range[0],
+          //       sourceCode.getLastToken(node).range[1],
+          //     ],
+          //     `Services.${serviceName}`
+          //   );
+          // },
+        });
+      },
+    };
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/use-static-import.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/use-static-import.js
new file mode 100644
index 0000000000..8b68eca867
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/use-static-import.js
@@ -0,0 +1,87 @@
+/**
+ * @fileoverview Require use of static imports where possible.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+const helpers = require("../helpers");
+
+function isIdentifier(node, id) {
+  return node && node.type === "Identifier" && node.name === id;
+}
+
+module.exports = {
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/use-static-import.html",
+    },
+    fixable: "code",
+    messages: {
+      useStaticImport:
+        "Please use static import instead of ChromeUtils.importESModule",
+    },
+    schema: [],
+    type: "suggestion",
+  },
+
+  create(context) {
+    return {
+      VariableDeclarator(node) {
+        if (
+          node.init?.type != "CallExpression" ||
+          node.init?.callee?.type != "MemberExpression" ||
+          !context.getFilename().endsWith(".sys.mjs") ||
+          !helpers.isTopLevel(context.getAncestors())
+        ) {
+          return;
+        }
+
+        let callee = node.init.callee;
+
+        if (
+          isIdentifier(callee.object, "ChromeUtils") &&
+          isIdentifier(callee.property, "importESModule") &&
+          callee.parent.arguments.length == 1
+        ) {
+          let sourceCode = context.getSourceCode();
+          let importItemSource;
+          if (node.id.type != "ObjectPattern") {
+            importItemSource = sourceCode.getText(node.id);
+          } else {
+            importItemSource = "{ ";
+            let initial = true;
+            for (let property of node.id.properties) {
+              if (!initial) {
+                importItemSource += ", ";
+              }
+              initial = false;
+              if (property.key.name == property.value.name) {
+                importItemSource += property.key.name;
+              } else {
+                importItemSource += `${property.key.name} as ${property.value.name}`;
+              }
+            }
+            importItemSource += " }";
+          }
+
+          context.report({
+            node: node.parent,
+            messageId: "useStaticImport",
+            fix(fixer) {
+              return fixer.replaceText(
+                node.parent,
+                `import ${importItemSource} from ${sourceCode.getText(
+                  callee.parent.arguments[0]
+                )}`
+              );
+            },
+          });
+        }
+      },
+    };
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/valid-ci-uses.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/valid-ci-uses.js
new file mode 100644
index 0000000000..e88a333cda
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/valid-ci-uses.js
@@ -0,0 +1,167 @@
+/**
+ * @fileoverview Reject uses of unknown interfaces on Ci and properties of those
+ * interfaces.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+const os = require("os");
+const helpers = require("../helpers");
+
+// These interfaces are all platform specific, so may be not present
+// on all platforms.
+const platformSpecificInterfaces = new Map([
+  ["nsIAboutThirdParty", "windows"],
+  ["nsIAboutWindowsMessages", "windows"],
+  ["nsIJumpListItem", "windows"],
+  ["nsIJumpListLink", "windows"],
+  ["nsIJumpListSeparator", "windows"],
+  ["nsIJumpListShortcut", "windows"],
+  ["nsITaskbarWindowPreview", "windows"],
+  ["nsIWindowsAlertsService", "windows"],
+  ["nsIWinAppHelper", "windows"],
+  ["nsIWinTaskbar", "windows"],
+  ["nsIWinTaskSchedulerService", "windows"],
+  ["nsIWindowsRegKey", "windows"],
+  ["nsIWindowsPackageManager", "windows"],
+  ["nsIWindowsShellService", "windows"],
+  ["nsIAccessibleMacEvent", "darwin"],
+  ["nsIAccessibleMacInterface", "darwin"],
+  ["nsILocalFileMac", "darwin"],
+  ["nsIAccessibleMacEvent", "darwin"],
+  ["nsIMacAttributionService", "darwin"],
+  ["nsIMacShellService", "darwin"],
+  ["nsIMacDockSupport", "darwin"],
+  ["nsIMacFinderProgress", "darwin"],
+  ["nsIMacPreferencesReader", "darwin"],
+  ["nsIMacSharingService", "darwin"],
+  ["nsIMacUserActivityUpdater", "darwin"],
+  ["nsIMacWebAppUtils", "darwin"],
+  ["nsIStandaloneNativeMenu", "darwin"],
+  ["nsITouchBarHelper", "darwin"],
+  ["nsITouchBarInput", "darwin"],
+  ["nsITouchBarUpdater", "darwin"],
+  ["mozISandboxReporter", "linux"],
+  ["nsIApplicationChooser", "linux"],
+  ["nsIGNOMEShellService", "linux"],
+  ["nsIGtkTaskbarProgress", "linux"],
+
+  // These are used in the ESLint test code.
+  ["amIFoo", "any"],
+  ["nsIMeh", "any"],
+  // Can't easily detect android builds from ESLint at the moment.
+  ["nsIAndroidBridge", "any"],
+  ["nsIAndroidView", "any"],
+  // Code coverage is enabled only for certain builds (MOZ_CODE_COVERAGE).
+  ["nsICodeCoverage", "any"],
+  // Layout debugging is enabled only for certain builds (MOZ_LAYOUT_DEBUGGER).
+  ["nsILayoutDebuggingTools", "any"],
+  // Sandbox test is only enabled for certain configurations (MOZ_SANDBOX,
+  // MOZ_DEBUG, ENABLE_TESTS).
+  ["mozISandboxTest", "any"],
+]);
+
+function interfaceHasProperty(interfaceName, propertyName) {
+  // `Ci.nsIFoo.number` is valid, it returns the iid.
+  if (propertyName == "number") {
+    return true;
+  }
+
+  let interfaceInfo = helpers.xpidlData.get(interfaceName);
+
+  if (!interfaceInfo) {
+    return true;
+  }
+
+  // If the property is not in the lists of consts for this interface, check
+  // any parents as well.
+  if (!interfaceInfo.consts.find(e => e.name === propertyName)) {
+    if (interfaceInfo.parent && interfaceInfo.parent != "nsISupports") {
+      return interfaceHasProperty(interfaceName.parent, propertyName);
+    }
+    return false;
+  }
+  return true;
+}
+
+module.exports = {
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/valid-ci-uses.html",
+    },
+    messages: {
+      missingInterface:
+        "{{ interface }} is defined in this rule's platform specific list, but is not available",
+      unknownInterface: "Use of unknown interface Ci.{{ interface}}",
+      unknownProperty:
+        "Use of unknown property Ci.{{ interface }}.{{ property }}",
+    },
+    schema: [],
+    type: "problem",
+  },
+
+  create(context) {
+    return {
+      MemberExpression(node) {
+        if (
+          node.computed === false &&
+          node.type === "MemberExpression" &&
+          node.object.type === "Identifier" &&
+          node.object.name === "Ci" &&
+          node.property.type === "Identifier" &&
+          node.property.name.includes("I")
+        ) {
+          if (!helpers.xpidlData.get(node.property.name)) {
+            let platformSpecific = platformSpecificInterfaces.get(
+              node.property.name
+            );
+            if (!platformSpecific) {
+              context.report({
+                node,
+                messageId: "unknownInterface",
+                data: {
+                  interface: node.property.name,
+                },
+              });
+            } else if (platformSpecific == os.platform) {
+              context.report({
+                node,
+                messageId: "missingInterface",
+                data: {
+                  interface: node.property.name,
+                },
+              });
+            }
+          }
+        }
+
+        if (
+          node.computed === false &&
+          node.object.type === "MemberExpression" &&
+          node.object.object.type === "Identifier" &&
+          node.object.object.name === "Ci" &&
+          node.object.property.type === "Identifier" &&
+          node.object.property.name.includes("I") &&
+          node.property.type === "Identifier"
+        ) {
+          if (
+            !interfaceHasProperty(node.object.property.name, node.property.name)
+          ) {
+            context.report({
+              node,
+              messageId: "unknownProperty",
+              data: {
+                interface: node.object.property.name,
+                property: node.property.name,
+              },
+            });
+          }
+        }
+      },
+    };
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/valid-lazy.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/valid-lazy.js
new file mode 100644
index 0000000000..52ad4ce7d5
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/valid-lazy.js
@@ -0,0 +1,221 @@
+/**
+ * @fileoverview Ensures that definitions and uses of properties on the
+ * ``lazy`` object are valid.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+const helpers = require("../helpers");
+
+const items = [
+  "loader",
+  "XPCOMUtils",
+  "Integration",
+  "ChromeUtils",
+  "DevToolsUtils",
+  "Object",
+  "Reflect",
+];
+
+const callExpressionDefinitions = [
+  /^loader\.lazyGetter\(lazy, "(\w+)"/,
+  /^loader\.lazyServiceGetter\(lazy, "(\w+)"/,
+  /^loader\.lazyRequireGetter\(lazy, "(\w+)"/,
+  /^XPCOMUtils\.defineLazyGetter\(lazy, "(\w+)"/,
+  /^Integration\.downloads\.defineESModuleGetter\(lazy, "(\w+)"/,
+  /^XPCOMUtils\.defineLazyModuleGetter\(lazy, "(\w+)"/,
+  /^ChromeUtils\.defineLazyGetter\(lazy, "(\w+)"/,
+  /^ChromeUtils\.defineModuleGetter\(lazy, "(\w+)"/,
+  /^XPCOMUtils\.defineLazyPreferenceGetter\(lazy, "(\w+)"/,
+  /^XPCOMUtils\.defineLazyProxy\(lazy, "(\w+)"/,
+  /^XPCOMUtils\.defineLazyScriptGetter\(lazy, "(\w+)"/,
+  /^XPCOMUtils\.defineLazyServiceGetter\(lazy, "(\w+)"/,
+  /^XPCOMUtils\.defineConstant\(lazy, "(\w+)"/,
+  /^DevToolsUtils\.defineLazyModuleGetter\(lazy, "(\w+)"/,
+  /^DevToolsUtils\.defineLazyGetter\(lazy, "(\w+)"/,
+  /^Object\.defineProperty\(lazy, "(\w+)"/,
+  /^Reflect\.defineProperty\(lazy, "(\w+)"/,
+];
+
+const callExpressionMultiDefinitions = [
+  "ChromeUtils.defineESModuleGetters(lazy,",
+  "XPCOMUtils.defineLazyModuleGetters(lazy,",
+  "XPCOMUtils.defineLazyServiceGetters(lazy,",
+  "Object.defineProperties(lazy,",
+  "loader.lazyRequireGetter(lazy,",
+];
+
+module.exports = {
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/valid-lazy.html",
+    },
+    messages: {
+      duplicateSymbol: "Duplicate symbol {{name}} being added to lazy.",
+      incorrectType: "Unexpected literal for property name {{name}}",
+      unknownProperty: "Unknown lazy member property {{name}}",
+      unusedProperty: "Unused lazy property {{name}}",
+      topLevelAndUnconditional:
+        "Lazy property {{name}} is used at top-level unconditionally. It should be non-lazy.",
+    },
+    schema: [],
+    type: "problem",
+  },
+
+  create(context) {
+    let lazyProperties = new Map();
+    let unknownProperties = [];
+
+    function addProp(node, name) {
+      if (lazyProperties.has(name)) {
+        context.report({
+          node,
+          messageId: "duplicateSymbol",
+          data: { name },
+        });
+        return;
+      }
+      lazyProperties.set(name, { used: false, node });
+    }
+
+    function setPropertiesFromArgument(node, arg) {
+      if (arg.type === "ObjectExpression") {
+        for (let prop of arg.properties) {
+          if (prop.key.type == "Literal") {
+            context.report({
+              node,
+              messageId: "incorrectType",
+              data: { name: prop.key.value },
+            });
+            continue;
+          }
+          addProp(node, prop.key.name);
+        }
+      } else if (arg.type === "ArrayExpression") {
+        for (let prop of arg.elements) {
+          if (prop.type != "Literal") {
+            continue;
+          }
+          addProp(node, prop.value);
+        }
+      }
+    }
+
+    return {
+      VariableDeclarator(node) {
+        if (
+          node.id.type === "Identifier" &&
+          node.id.name == "lazy" &&
+          node.init.type == "CallExpression" &&
+          node.init.callee.name == "createLazyLoaders"
+        ) {
+          setPropertiesFromArgument(node, node.init.arguments[0]);
+        }
+      },
+
+      CallExpression(node) {
+        if (
+          node.callee.type != "MemberExpression" ||
+          (node.callee.object.type == "MemberExpression" &&
+            !items.includes(node.callee.object.object.name)) ||
+          (node.callee.object.type != "MemberExpression" &&
+            !items.includes(node.callee.object.name))
+        ) {
+          return;
+        }
+
+        let source;
+        try {
+          source = helpers.getASTSource(node);
+        } catch (e) {
+          return;
+        }
+
+        for (let reg of callExpressionDefinitions) {
+          let match = source.match(reg);
+          if (match) {
+            if (lazyProperties.has(match[1])) {
+              context.report({
+                node,
+                messageId: "duplicateSymbol",
+                data: { name: match[1] },
+              });
+              return;
+            }
+            lazyProperties.set(match[1], { used: false, node });
+            break;
+          }
+        }
+
+        if (
+          callExpressionMultiDefinitions.some(expr =>
+            source.startsWith(expr)
+          ) &&
+          node.arguments[1]
+        ) {
+          setPropertiesFromArgument(node, node.arguments[1]);
+        }
+      },
+
+      MemberExpression(node) {
+        if (node.computed || node.object.type !== "Identifier") {
+          return;
+        }
+
+        let name;
+        if (node.object.name == "lazy") {
+          name = node.property.name;
+        } else {
+          return;
+        }
+        let property = lazyProperties.get(name);
+        if (!property) {
+          // These will be reported on Program:exit - some definitions may
+          // be after first use, so we need to wait until we've processed
+          // the whole file before reporting.
+          unknownProperties.push({ name, node });
+        } else {
+          property.used = true;
+        }
+        if (
+          helpers.getIsTopLevelAndUnconditionallyExecuted(
+            context.getAncestors()
+          )
+        ) {
+          context.report({
+            node,
+            messageId: "topLevelAndUnconditional",
+            data: { name },
+          });
+        }
+      },
+
+      "Program:exit": function () {
+        for (let { name, node } of unknownProperties) {
+          let property = lazyProperties.get(name);
+          if (!property) {
+            context.report({
+              node,
+              messageId: "unknownProperty",
+              data: { name },
+            });
+          } else {
+            property.used = true;
+          }
+        }
+        for (let [name, property] of lazyProperties.entries()) {
+          if (!property.used) {
+            context.report({
+              node: property.node,
+              messageId: "unusedProperty",
+              data: { name },
+            });
+          }
+        }
+      },
+    };
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/valid-services-property.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/valid-services-property.js
new file mode 100644
index 0000000000..d0a8b2710a
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/valid-services-property.js
@@ -0,0 +1,126 @@
+/**
+ * @fileoverview Ensures that property accesses on Services.<alias> are valid.
+ * Although this largely duplicates the valid-services rule, the checks here
+ * require an objdir and a manual run.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+const helpers = require("../helpers");
+
+function findInterfaceNames(name) {
+  let interfaces = [];
+  for (let [key, value] of Object.entries(helpers.servicesData)) {
+    if (value == name) {
+      interfaces.push(key);
+    }
+  }
+  return interfaces;
+}
+
+function isInInterface(interfaceName, name) {
+  let interfaceDetails = helpers.xpidlData.get(interfaceName);
+
+  // TODO: Bug 1790261 - check only methods if the expression is callable.
+  if (interfaceDetails.methods.some(m => m.name == name)) {
+    return true;
+  }
+
+  if (interfaceDetails.consts.some(c => c.name == name)) {
+    return true;
+  }
+
+  if (interfaceDetails.parent) {
+    return isInInterface(interfaceDetails.parent, name);
+  }
+  return false;
+}
+
+module.exports = {
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/valid-services-property.html",
+    },
+    messages: {
+      unknownProperty:
+        "Unknown property access Services.{{ alias }}.{{ propertyName }}, Interfaces: {{ checkedInterfaces }}",
+    },
+    schema: [],
+    type: "problem",
+  },
+
+  create(context) {
+    let servicesInterfaceMap = helpers.servicesData;
+    let serviceAliases = new Set([
+      ...Object.values(servicesInterfaceMap),
+      // This is defined only for Android, so most builds won't pick it up.
+      "androidBridge",
+      // These are defined without interfaces and hence are not in the services map.
+      "cpmm",
+      "crashmanager",
+      "mm",
+      "ppmm",
+      // The new xulStore also does not have an interface.
+      "xulStore",
+    ]);
+    return {
+      MemberExpression(node) {
+        if (node.computed || node.object.type !== "Identifier") {
+          return;
+        }
+
+        let mainNode;
+        if (node.object.name == "Services") {
+          mainNode = node;
+        } else if (
+          node.property.name == "Services" &&
+          node.parent.type == "MemberExpression"
+        ) {
+          mainNode = node.parent;
+        } else {
+          return;
+        }
+
+        let alias = mainNode.property.name;
+        if (!serviceAliases.has(alias)) {
+          return;
+        }
+
+        if (
+          mainNode.parent.type == "MemberExpression" &&
+          !mainNode.parent.computed
+        ) {
+          let propertyName = mainNode.parent.property.name;
+          if (propertyName == "wrappedJSObject") {
+            return;
+          }
+          let interfaces = findInterfaceNames(alias);
+          if (!interfaces.length) {
+            return;
+          }
+
+          let checkedInterfaces = [];
+          for (let item of interfaces) {
+            if (isInInterface(item, propertyName)) {
+              return;
+            }
+            checkedInterfaces.push(item);
+          }
+          context.report({
+            node,
+            messageId: "unknownProperty",
+            data: {
+              alias,
+              propertyName,
+              checkedInterfaces,
+            },
+          });
+        }
+      },
+    };
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/valid-services.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/valid-services.js
new file mode 100644
index 0000000000..eb28087fe9
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/valid-services.js
@@ -0,0 +1,62 @@
+/**
+ * @fileoverview Ensures that Services uses have valid property names.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+const helpers = require("../helpers");
+
+module.exports = {
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/valid-services.html",
+    },
+    schema: [],
+    type: "problem",
+  },
+
+  create(context) {
+    let servicesInterfaceMap = helpers.servicesData;
+    let serviceAliases = new Set([
+      ...Object.values(servicesInterfaceMap),
+      // This is defined only for Android, so most builds won't pick it up.
+      "androidBridge",
+      // These are defined without interfaces and hence are not in the services map.
+      "cpmm",
+      "crashmanager",
+      "mm",
+      "ppmm",
+      // The new xulStore also does not have an interface.
+      "xulStore",
+    ]);
+    return {
+      MemberExpression(node) {
+        if (node.computed || node.object.type !== "Identifier") {
+          return;
+        }
+
+        let alias;
+        if (node.object.name == "Services") {
+          alias = node.property.name;
+        } else if (
+          node.property.name == "Services" &&
+          node.parent.type == "MemberExpression"
+        ) {
+          alias = node.parent.property.name;
+        } else {
+          return;
+        }
+
+        if (!serviceAliases.has(alias)) {
+          context.report({
+            node,
+            message: `Unknown Services member property ${alias}`,
+          });
+        }
+      },
+    };
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/var-only-at-top-level.js b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/var-only-at-top-level.js
new file mode 100644
index 0000000000..64c7298d1f
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/rules/var-only-at-top-level.js
@@ -0,0 +1,39 @@
+/**
+ * @fileoverview Marks all var declarations that are not at the top level
+ *               invalid.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+"use strict";
+
+var helpers = require("../helpers");
+
+module.exports = {
+  meta: {
+    docs: {
+      url: "https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/var-only-at-top-level.html",
+    },
+    schema: [],
+    type: "suggestion",
+  },
+
+  create(context) {
+    return {
+      VariableDeclaration(node) {
+        if (node.kind === "var") {
+          if (helpers.getIsTopLevelScript(context.getAncestors())) {
+            return;
+          }
+
+          context.report({
+            node,
+            message: "Unexpected var, use let or const instead.",
+          });
+        }
+      },
+    };
+  },
+};
diff --git a/tools/lint/eslint/eslint-plugin-mozilla/lib/services.json b/tools/lint/eslint/eslint-plugin-mozilla/lib/services.json
new file mode 100644
index 0000000000..91442fdda3
--- /dev/null
+++ b/tools/lint/eslint/eslint-plugin-mozilla/lib/services.json
@@ -0,0 +1,62 @@
+{
+  "mozIJSSubScriptLoader": "scriptloader",
+  "mozILocaleService": "locale",
+  "mozIMozIntl": "intl",
+  "mozIStorageService": "storage",
+  "nsIAppShellService": "appShell",
+  "nsIAppStartup": "startup",
+  "nsIBlocklistService": "blocklist",
+  "nsICacheStorageService": "cache2",
+  "nsICategoryManager": "catMan",
+  "nsIClearDataService": "clearData",
+  "nsIClipboard": "clipboard",
+  "nsIConsoleService": "console",
+  "nsICookieBannerService": "cookieBanners",
+  "nsICookieManager": "cookies",
+  "nsICookieService": "cookies",
+  "nsICrashReporter": "appinfo",
+  "nsIDAPTelemetry": "DAPTelemetry",
+  "nsIDOMRequestService": "DOMRequest",
+  "nsIDOMStorageManager": "domStorageManager",
+  "nsIDNSService": "dns",
+  "nsIDirectoryService": "dirsvc",
+  "nsIDroppedLinkHandler": "droppedLinkHandler",
+  "nsIEffectiveTLDService": "eTLD",
+  "nsIEnterprisePolicies": "policies",
+  "nsIEnvironment": "env",
+  "nsIEventListenerService": "els",
+  "nsIFOG": "fog",
+  "nsIFocusManager": "focus",
+  "nsIIOService": "io",
+  "nsILoadContextInfoFactory": "loadContextInfo",
+  "nsILocalStorageManager": "domStorageManager",
+  "nsILoginManager": "logins",
+  "nsINetUtil": "io",
+  "nsIObserverService": "obs",
+  "nsIPermissionManager": "perms",
+  "nsIPrefBranch": "prefs",
+  "nsIPrefService": "prefs",
+  "nsIProfiler": "profiler",
+  "nsIPromptService": "prompt",
+  "nsIProperties": "dirsvc",
+  "nsIPropertyBag2": "sysinfo",
+  "nsIQuotaManagerService": "qms",
+  "nsIScriptSecurityManager": "scriptSecurityManager",
+  "nsISearchService": "search",
+  "nsISessionStorageService": "sessionStorage",
+  "nsISpeculativeConnect": "io",
+  "nsIStringBundleService": "strings",
+  "nsISystemInfo": "sysinfo",
+  "nsITelemetry": "telemetry",
+  "nsITextToSubURI": "textToSubURI",
+  "nsIThreadManager": "tm",
+  "nsIURIFixup": "uriFixup",
+  "nsIURLFormatter": "urlFormatter",
+  "nsIUUIDGenerator": "uuid",
+  "nsIVersionComparator": "vc",
+  "nsIWindowMediator": "wm",
+  "nsIWindowWatcher": "ww",
+  "nsIXULAppInfo": "appinfo",
+  "nsIXULRuntime": "appinfo",
+  "nsIXULStore": "xulStore"
+}