/* This Source Code Form is subject to the terms of the Mozilla Public * License, v. 2.0. If a copy of the MPL was not distributed with this file, * You can obtain one at http://mozilla.org/MPL/2.0/. */ "use strict"; /** * The configuration is based on eslint:recommended config. The details for all * the ESLint rules, and which ones are in the recommended configuration can * be found here: * * https://eslint.org/docs/rules/ * * Rules that we've explicitly decided not to enable: * * require-await - bug 1381030. * no-prototype-builtins - bug 1551829. * require-atomic-updates - bug 1551829. * - This generates too many false positives that are not easy to work * around, and false positives seem to be inherent in the rule. * no-inner-declarations - bug 1487642. * - Would be interested if this could apply to just vars, but at the moment * it doesn't. * max-depth * - Don't enforce the maximum depth that blocks can be nested. The * complexity rule is a better rule to check this. * no-useless-escape - bug 1881262. * - This doesn't reveal any actual errors, and is a lot of work to address. */ module.exports = { env: { browser: true, es2022: true, "mozilla/privileged": true, "mozilla/specific": true, }, // The prettier configuration here comes from eslint-config-prettier and // turns off all of ESLint's rules related to formatting. extends: [ "eslint:recommended", "prettier", "plugin:json/recommended-with-comments", ], overrides: [ { // System mjs files and jsm files are not loaded in the browser scope, // so we turn that off for those. Though we do have our own special // environment for them. env: { browser: false, "mozilla/sysmjs": true, }, files: ["**/*.sys.mjs", "**/*.jsm"], rules: { "mozilla/lazy-getter-object-name": "error", "mozilla/reject-eager-module-in-lazy-getter": "error", "mozilla/reject-global-this": "error", "mozilla/reject-globalThis-modification": "error", // For all system modules, we expect no properties to need importing, // hence reject everything. "mozilla/reject-importGlobalProperties": ["error", "everything"], "mozilla/reject-mixing-eager-and-lazy": "error", "mozilla/reject-top-level-await": "error", // TODO: Bug 1575506 turn `builtinGlobals` on here. // We can enable builtinGlobals for jsms due to their scopes. "no-redeclare": ["error", { builtinGlobals: false }], }, }, { files: ["**/*.mjs", "**/*.jsx", "**/*.jsm", "**/?(*.)worker.?(m)js"], rules: { // Modules and workers are far easier to check for no-unused-vars on a // global scope, than our content files. Hence we turn that on here. "no-unused-vars": [ "error", { args: "none", vars: "all", }, ], }, }, { excludedFiles: ["**/*.sys.mjs"], files: ["**/*.mjs"], rules: { "mozilla/reject-import-system-module-from-non-system": "error", "mozilla/reject-lazy-imports-into-globals": "error", "no-shadow": ["error", { allow: ["event"], builtinGlobals: true }], }, }, { files: ["**/*.mjs", "**/*.jsx"], parserOptions: { sourceType: "module", }, rules: { "mozilla/use-static-import": "error", // This rule defaults to not allowing "use strict" in module files since // they are always loaded in strict mode. strict: "error", }, }, { files: ["**/*.jsm"], rules: { "mozilla/mark-exported-symbols-as-used": "error", }, }, { env: { browser: false, "mozilla/privileged": false, "mozilla/sjs": true, "mozilla/specific": false, }, files: ["**/*.sjs"], rules: { // For sjs files, reject everything as we should update the sandbox // to include the globals we need, as these are test-only files. "mozilla/reject-importGlobalProperties": ["error", "everything"], }, }, { env: { browser: false, worker: true, }, files: [ // Most files should use the `.worker.` format to be consistent with // other items like `.sys.mjs`, but we allow simply calling the file // "worker" as well. "**/?(*.)worker.?(m)js", ], }, ], parserOptions: { ecmaVersion: "latest", }, // When adding items to this file please check for effects on sub-directories. plugins: ["fetch-options", "html", "json", "no-unsanitized"], // When adding items to this file please check for effects on all of toolkit // and browser rules: { // This may conflict with prettier, so we turn it off. "arrow-body-style": "off", // Warn about cyclomatic complexity in functions. // XXX Get this down to 20? complexity: ["error", 34], // Functions must always return something or nothing "consistent-return": "error", // Require braces around blocks that start a new line curly: ["error", "all"], // Encourage the use of dot notation whenever possible. "dot-notation": "error", // XXX This rule should be enabled, see Bug 1557040 // No credentials submitted with fetch calls "fetch-options/no-fetch-credentials": "off", // Maximum depth callbacks can be nested. "max-nested-callbacks": ["error", 10], "mozilla/avoid-removeChild": "error", "mozilla/consistent-if-bracing": "error", "mozilla/import-browser-window-globals": "error", "mozilla/import-globals": "error", "mozilla/no-compare-against-boolean-literals": "error", "mozilla/no-cu-reportError": "error", "mozilla/no-define-cc-etc": "error", "mozilla/no-throw-cr-literal": "error", "mozilla/no-useless-parameters": "error", "mozilla/no-useless-removeEventListener": "error", "mozilla/prefer-boolean-length-check": "error", "mozilla/prefer-formatValues": "error", "mozilla/reject-addtask-only": "error", "mozilla/reject-chromeutils-import-params": "error", "mozilla/reject-importGlobalProperties": ["error", "allownonwebidl"], "mozilla/reject-multiple-getters-calls": "error", "mozilla/reject-scriptableunicodeconverter": "warn", "mozilla/rejects-requires-await": "error", "mozilla/use-cc-etc": "error", "mozilla/use-chromeutils-definelazygetter": "error", "mozilla/use-chromeutils-generateqi": "error", "mozilla/use-chromeutils-import": "error", "mozilla/use-console-createInstance": "error", "mozilla/use-default-preference-values": "error", "mozilla/use-includes-instead-of-indexOf": "error", "mozilla/use-isInstance": "error", "mozilla/use-ownerGlobal": "error", "mozilla/use-returnValue": "error", "mozilla/use-services": "error", "mozilla/valid-lazy": "error", "mozilla/valid-services": "error", // Use [] instead of Array() "no-array-constructor": "error", // Disallow use of arguments.caller or arguments.callee. "no-caller": "error", // Disallow the use of console, except for errors and warnings. "no-console": ["error", { allow: ["createInstance", "error", "warn"] }], // Disallows expressions where the operation doesn't affect the value. // TODO: This is enabled by default in ESLint's v9 recommended configuration. "no-constant-binary-expression": "error", // If an if block ends with a return no need for an else block "no-else-return": "error", // No empty statements "no-empty": ["error", { allowEmptyCatch: true }], // Disallow empty static blocks. // This rule will be a recommended rule in ESLint v9 so may be removed // when we upgrade to that. "no-empty-static-block": "error", // Disallow eval and setInteral/setTimeout with strings "no-eval": "error", // Disallow unnecessary calls to .bind() "no-extra-bind": "error", // Disallow fallthrough of case statements "no-fallthrough": [ "error", { // The eslint rule doesn't allow for case-insensitive regex option. // The following pattern allows for a dash between "fall through" as // well as alternate spelling of "fall thru". The pattern also allows // for an optional "s" at the end of "fall" ("falls through"). commentPattern: "[Ff][Aa][Ll][Ll][Ss]?[\\s-]?([Tt][Hh][Rr][Oo][Uu][Gg][Hh]|[Tt][Hh][Rr][Uu])", }, ], // Disallow eval and setInteral/setTimeout with strings "no-implied-eval": "error", // See explicit decisions at top of file. "no-inner-declarations": "off", // Disallow the use of the __iterator__ property "no-iterator": "error", // No labels "no-labels": "error", // Disallow unnecessary nested blocks "no-lone-blocks": "error", // No single if block inside an else block "no-lonely-if": "error", // Nested ternary statements are confusing "no-nested-ternary": "error", // Disallow new operators with global non-constructor functions. // This rule will be a recommended rule in ESLint v9 so may be removed // when we upgrade to that. "no-new-native-nonconstructor": "error", // Disallow use of new wrappers "no-new-wrappers": "error", // Use {} instead of new Object(), unless arguments are passed. "no-object-constructor": "error", // We don't want this, see bug 1551829 "no-prototype-builtins": "off", // Disable builtinGlobals for no-redeclare as this conflicts with our // globals declarations especially for browser window. "no-redeclare": ["error", { builtinGlobals: false }], // Disallow use of event global. "no-restricted-globals": ["error", "event"], // No unnecessary comparisons "no-self-compare": "error", // No comma sequenced statements "no-sequences": "error", // No declaring variables from an outer scope // "no-shadow": "error", // Disallow throwing literals (eg. throw "error" instead of // throw new Error("error")). "no-throw-literal": "error", // Disallow the use of Boolean literals in conditional expressions. "no-unneeded-ternary": "error", // No unsanitized use of innerHTML=, document.write() etc. // cf. https://github.com/mozilla/eslint-plugin-no-unsanitized#rule-details "no-unsanitized/method": "error", "no-unsanitized/property": "error", // Disallow unused private class members. // This rule will be a recommended rule in ESLint v9 so may be removed // when we upgrade to that. "no-unused-private-class-members": "error", // No declaring variables that are never used "no-unused-vars": [ "error", { args: "none", vars: "local", }, ], // No using variables before defined // "no-use-before-define": ["error", "nofunc"], // Disallow unnecessary .call() and .apply() "no-useless-call": "error", // Don't concatenate string literals together (unless they span multiple // lines) "no-useless-concat": "error", // See explicit decisions at top of file. "no-useless-escape": "off", // Disallow redundant return statements "no-useless-return": "error", // Require object-literal shorthand with ES6 method syntax "object-shorthand": ["error", "always", { avoidQuotes: true }], // This may conflict with prettier, so turn it off. "prefer-arrow-callback": "off", }, };