.eslintrc.cjs

/**
 * @license Copyright 2017 The Lighthouse Authors. All Rights Reserved.
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
 * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.
 */
'use strict';

/**
 * eslint does not support ESM rc files, so this must be a .cjs file.
 * @see https://eslint.org/docs/user-guide/configuring/configuration-files#configuration-file-formats
 * @see https://github.com/eslint/eslint/issues/13481
 */

module.exports = {
  // All subdirectory eslintrcs extend from this one.
  root: true,
  // start with google standard style
  //     https://github.com/google/eslint-config-google/blob/master/index.js
  extends: ['eslint:recommended', 'google'],
  plugins: [
    'eslint-plugin-local-rules',
    'eslint-plugin-import',
  ],
  env: {
    node: true,
    es6: true,
  },
  rules: {
    // 2 == error, 1 == warning, 0 == off
    'import/order': [2, {
      'groups': [
        'builtin',
        'external',
        ['sibling', 'parent'],
        'index',
        'object',
        'type',
      ],
      'newlines-between': 'always',
    }],
    'import/group-exports': 2,
    'import/exports-last': 2,
    'eqeqeq': 2,
    'indent': [2, 2, {
      SwitchCase: 1,
      VariableDeclarator: 2,
      CallExpression: {arguments: 'off'},
      MemberExpression: 'off',
      FunctionExpression: {body: 1, parameters: 2},
      ignoredNodes: [
        'ConditionalExpression > :matches(.consequent, .alternate)',
        'VariableDeclarator > ArrowFunctionExpression > :expression.body',
        'CallExpression > ArrowFunctionExpression > :expression.body',
      ],
    }],
    'no-floating-decimal': 2,
    'max-len': [2, 100, {
      ignorePattern: 'readJson\\(|^import ',
      ignoreComments: true,
      ignoreUrls: true,
      tabWidth: 2,
    }],
    'no-empty': [2, {
      allowEmptyCatch: true,
    }],
    'no-implicit-coercion': [2, {
      boolean: false,
      number: true,
      string: true,
    }],
    'no-unused-expressions': [2, {
      allowShortCircuit: true,
      allowTernary: false,
    }],
    'no-unused-vars': [2, {
      vars: 'all',
      args: 'after-used',
      argsIgnorePattern: '(^reject$|^_+$)',
      varsIgnorePattern: '(^_$|^LH$)',
    }],
    'no-cond-assign': 2,
    'space-infix-ops': 2,
    'strict': [2, 'global'],
    'prefer-const': 2,
    'curly': [2, 'multi-line'],
    'comma-dangle': [2, {
      arrays: 'always-multiline',
      objects: 'always-multiline',
      imports: 'always-multiline',
      exports: 'always-multiline',
      functions: 'never',
    }],
    'operator-linebreak': ['error', 'after', {'overrides': {'?': 'ignore', ':': 'ignore'}}],

    // Custom lighthouse rules
    'local-rules/require-file-extension': 2,

    // Disabled rules
    'require-jsdoc': 0,
    'valid-jsdoc': 0,
    'arrow-parens': 0,
  },
  overrides: [
    {
      files: ['cli/test/smokehouse/test-definitions/*.js'],
      rules: {
        'max-len': 0,
      },
    },
  ],
  parser: '@typescript-eslint/parser',
  parserOptions: {
    ecmaVersion: 2020,
    ecmaFeatures: {
      globalReturn: true,
      jsx: false,
    },
    sourceType: 'module',
  },
};