.eslintrc.js

module.exports = {
  env: {
    browser: true,
    commonjs: true,
    es2021: true
  },
  extends: [
    'eslint:recommended',
    'plugin:unicorn/recommended',
    'plugin:jest/recommended',
    'plugin:jest/style',
    'plugin:import/recommended',
    'prettier'
  ],
  parser: '@babel/eslint-parser',
  parserOptions: {
    ecmaVersion: 12,
    requireConfigFile: false
  },
  plugins: ['prettier', 'unicorn', 'import'],
  overrides: [
    {
      files: 'server.js',
      env: {browser: false, node: true}
    },
    {
      files: './ext/**.js',
      env: {webextensions: true}
    }
  ],
  globals: {
    CodeMirror: 'writable',
    DarkReader: 'writable',
    ide: 'writable',
    chrome: 'writable',
    globalTemplate: 'writable',
    validPanelLst: 'writable',
    matchMultiple: 'writable',
    unpack: 'writable',
    XMLHttpRequest: 'writable',
    Sortable: 'writable'
  },
  rules: {
    'prettier/prettier': 'error',
    'import/extensions': ['error', 'always'],
    'accessor-pairs': 'error',
    'array-callback-return': 'error',
    'block-scoped-var': 'error',
    'camelcase': ['error', {ignoreImports: true}],
    'default-case-last': 'error',
    'dot-notation': 'error',
    'eqeqeq': 'error',
    'func-style': ['error', 'declaration', {allowArrowFunctions: true}],
    'grouped-accessor-pairs': 'error',
    'init-declarations': 'error',
    'lines-between-class-members': 'error',
    'multiline-comment-style': ['error', 'separate-lines'],
    'no-bitwise': 'error',
    'no-caller': 'error',
    'no-case-declarations': 'off',
    'no-constant-condition': ['error', {checkLoops: false}],
    'no-constructor-return': 'error',
    'no-duplicate-imports': ['error', {includeExports: true}],
    'no-else-return': 'error',
    'no-empty': ['error', {allowEmptyCatch: true}],
    'no-eval': 'error',
    'no-extend-native': 'error',
    'no-extra-bind': 'error',
    'no-extra-label': 'error',
    'no-global-assign': 'error',
    'no-implicit-coercion': 'error',
    'no-implied-eval': 'error',
    'no-inner-declarations': 'off',
    'no-iterator': 'error',
    'no-label-var': 'error',
    'no-lone-blocks': 'error',
    'no-lonely-if': 'error',
    'no-loss-of-precision': 'error',
    'no-multi-str': 'error',
    'no-negated-condition': 'error',
    'no-nested-ternary': 'error',
    'no-new-func': 'error',
    'no-new-wrappers': 'error',
    'no-nonoctal-decimal-escape': 'error',
    'no-octal-escape': 'error',
    'no-plusplus': ['error', {allowForLoopAfterthoughts: true}],
    'no-promise-executor-return': 'error',
    'no-proto': 'error',
    'no-return-assign': ['error', 'always'],
    'no-return-await': 'error',
    'no-script-url': 'error',
    'no-self-compare': 'error',
    'no-sequences': 'error',
    'no-template-curly-in-string': 'error',
    'no-throw-literal': 'error',
    'no-undef-init': 'error',
    'no-unneeded-ternary': 'error',
    'no-unreachable-loop': 'error',
    'no-unsafe-optional-chaining': 'error',
    'no-unused-expressions': 'error',
    'no-useless-backreference': 'error',
    'no-useless-call': 'error',
    'no-useless-computed-key': 'error',
    'no-useless-concat': 'error',
    'no-useless-constructor': 'error',
    'no-useless-rename': 'error',
    'no-useless-return': 'error',
    'no-var': 'error',
    'no-void': 'error',
    'object-shorthand': 'error',
    'one-var': ['error', 'never'],
    'operator-assignment': 'error',
    'prefer-destructuring': ['error', {VariableDeclarator: {object: true, array: true}, AssignmentExpression: {object: true, array: false}}],
    'prefer-exponentiation-operator': 'error',
    'prefer-numeric-literals': 'error',
    'prefer-object-spread': 'error',
    'prefer-regex-literals': ['error', {disallowRedundantWrapping: true}],
    'prefer-rest-params': 'error',
    'prefer-spread': 'error',
    'radix': 'error',
    'require-atomic-updates': 'error',
    'require-await': 'error',
    'spaced-comment': 'error',
    'strict': ['error', 'never'],
    'yoda': ['error', 'never'],

    // Unicorn rules
    'unicorn/catch-error-name': ['error', {name: 'error'}],
    'unicorn/consistent-function-scoping': 'off',
    'unicorn/no-array-callback-reference': 'off',
    'unicorn/no-array-reduce': 'off',
    'unicorn/no-null': 'off',
    'unicorn/prefer-add-event-listener': 'off',
    'unicorn/prefer-array-some': 'off',
    'unicorn/prefer-module': 'off',
    'unicorn/prefer-number-properties': 'off',
    'unicorn/prefer-query-selector': 'off',
    'unicorn/prefer-reflect-apply': 'off',
    'unicorn/prefer-string-replace-all': 'error',
    'unicorn/prevent-abbreviations': 'off',
    'unicorn/numeric-separators-style': 'error'
  }
};