Adding upstream version 115.8.0esr.upstream/115.8.0esr

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

55 files changed, 4380 insertions, 0 deletions

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.",
+          });
+        }
+      },
+    };
+  },
+};