.eslintrc.json

// Copyright 2020 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// See https://eslint.org/docs/user-guide/configuring.
// We need to use JSON rather than JS due to Node/ESLint conflicts over ESM:
// https://github.com/eslint/eslint/issues/12319

{
  "root": true,
  "env": {
    "node": true,
    // This allows the runtime environment (i.e. objects).
    "es6": true
  },
  "parserOptions": {
    // This sets the syntax parsing level.
    "ecmaVersion": 2020,
    "sourceType": "module"
  },

  "plugins": [
    "jsdoc"
  ],

  // See https://eslint.org/docs/rules/ for details.
  // These rules were picked based on the existing codebase.  If you find one
  // to be too onerous and not required by the styleguide, feel free to discuss.
  "rules": {
    "array-bracket-spacing": "error",
    "arrow-parens": ["error", "always"],
    "arrow-spacing": ["error", {"before": true, "after": true}],
    "block-spacing": ["error", "always"],
    "comma-dangle": ["error", "always-multiline"],
    "comma-spacing": "error",
    "comma-style": "error",
    "curly": "error",
    "default-param-last": "error",
    "eol-last": "error",
    "func-call-spacing": "error",
    "generator-star-spacing": ["error", "after"],
    // l/I: Depending on the font, these are hard to distinguish.
    "id-blacklist": ["error", "l", "I", "self"],
    "keyword-spacing": "error",
    "lines-between-class-members": "error",
    "max-len": ["error", {"code": 80, "ignoreUrls": true}],
    "new-parens": "error",
    "no-alert": "error",
    "no-case-declarations": "error",
    "no-cond-assign": "error",
    "no-const-assign": "error",
    "no-control-regex": "error",
    "no-debugger": "error",
    "no-dupe-args": "error",
    "no-dupe-class-members": "error",
    "no-dupe-keys": "error",
    "no-duplicate-case": "error",
    "no-empty": "error",
    "no-empty-character-class": "error",
    "no-eval": "error",
    "no-ex-assign": "error",
    // We want "all" (nestedBinaryExpressions=false), but this breaks
    // closure-compiler casts.
    "no-extra-parens": ["error", "functions"],
    "no-extra-semi": "error",
    "no-implied-eval": "error",
    "no-invalid-regexp": "error",
    "no-irregular-whitespace": "error",
    "no-label-var": "error",
    "no-mixed-spaces-and-tabs": "error",
    "no-multi-spaces": ["error", {"ignoreEOLComments": true}],
    "no-multiple-empty-lines": "error",
    "no-new": "error",
    "no-new-func": "error",
    "no-new-object": "error",
    "no-new-wrappers": "error",
    "no-obj-calls": "error",
    "no-octal": "error",
    "no-octal-escape": "error",
    "no-return-await": "error",
    "no-script-url": "error",
    "no-self-assign": "error",
    "no-self-compare": "error",
    "no-sequences": "error",
    "no-shadow-restricted-names": "error",
    "no-tabs": "error",
    "no-template-curly-in-string": "error",
    "no-throw-literal": "error",
    "no-trailing-spaces": "error",
    "no-unmodified-loop-condition": "error",
    "no-unneeded-ternary": "error",
    "no-unreachable": "error",
    "no-useless-call": "error",
    "no-useless-concat": "error",
    "no-useless-escape": "error",
    "no-useless-return": "error",
    "no-var": "error",
    "no-void": "error",
    // We allow TODO comments.
    "no-warning-comments": [
      "error", {
        "terms": ["fix", "fixme", "xxx"]
      }
    ],
    "no-whitespace-before-property": "error",
    "no-with": "error",
    "object-curly-newline": ["error", {"consistent": true}],
    "object-curly-spacing": "error",
    "one-var-declaration-per-line": "error",
    "prefer-const": "error",
    "prefer-numeric-literals": "error",
    "prefer-rest-params": "error",
    "quote-props": ["error", "consistent"],
    "quotes": ["error", "single",
               {"avoidEscape": true, "allowTemplateLiterals": true}],
    "radix": "error",
    "rest-spread-spacing": "error",
    "semi": ["error", "always"],
    "semi-spacing": "error",
    "semi-style": ["error", "last"],
    "space-before-blocks": ["error", "always"],
    "space-before-function-paren": [
      "error", {
        "anonymous": "never",
        "named": "never",
        "asyncArrow": "always"
      }
    ],
    "space-in-parens": ["error", "never"],
    "space-infix-ops": "error",
    "space-unary-ops": "error",
    "spaced-comment": ["error", "always"],
    "switch-colon-spacing": ["error", {"after": true, "before": false}],
    "symbol-description": "error",
    "template-curly-spacing": ["error", "never"],
    "unicode-bom": ["error", "never"],
    "use-isnan": "error",
    "valid-typeof": "error",
    "yield-star-spacing": ["error", "after"],
    "yoda": "error",

    "jsdoc/check-access": "error",
    "jsdoc/check-alignment": "error",
    "jsdoc/check-examples": "error",
    // We want hanging indentation, but this check requires none everywhere.
    "jsdoc/check-indentation": "off",
    "jsdoc/check-param-names": "error",
    "jsdoc/check-property-names": "error",
    // Make sure this is disabled as this rejects closure syntax.
    "jsdoc/check-syntax": "off",
    "jsdoc/check-tag-names": "error",
    // This is disabled until this crash is resolved:
    // https://github.com/gajus/eslint-plugin-jsdoc/issues/389
    "jsdoc/check-types": "off",
    // We don"t use these tags in the project.
    "jsdoc/check-values": "off",
    "jsdoc/empty-tags": "error",
    "jsdoc/implements-on-classes": "error",
    "jsdoc/match-description": "error",
    "jsdoc/newline-after-description": "error",
    // This is only for TypeScript which we don"t care about.
    "jsdoc/no-types": "off",
    "jsdoc/no-undefined-types": "error",
    "jsdoc/require-description": "error",
    // TODO(vapier): Turn this on.
    "jsdoc/require-description-complete-sentence": "off",
    // We don"t want to require examples.
    "jsdoc/require-example": "off",
    "jsdoc/require-file-overview": "error",
    "jsdoc/require-hyphen-before-param-description": ["error", "never"],
    "jsdoc/require-jsdoc": "error",
    "jsdoc/require-param": "error",
    "jsdoc/require-param-description": "error",
    "jsdoc/require-param-name": "error",
    "jsdoc/require-param-type": "error",
    "jsdoc/require-returns": "error",
    "jsdoc/require-returns-check": "error",
    "jsdoc/require-returns-description": "error",
    "jsdoc/require-returns-type": "error",
    "jsdoc/valid-types": "error"
  },

  "settings": {
    // https://github.com/gajus/eslint-plugin-jsdoc#eslint-plugin-jsdoc
    "jsdoc": {
      "mode": "closure",
      "preferredTypes": {
        "object": "Object"
      },
      "tagNamePreference": {
        // While not explicitly defined, Google/Chromium JS style guides only
        // use these keyword forms, as does the closure compiler docs.
        "augments": "extends",
        "constant": "const",
        "class": "constructor",
        "file": "fileoverview",
        "returns": "return",
        "yields": "yield"
      }
    }
  }
}