@procore/eslint-config/index.js

module.exports = {
  ignorePatterns: ['!.storybook'],
  root: true,
  extends: [
    'airbnb',
    'airbnb/hooks',
    'plugin:prettier/recommended',
    'prettier/react',
    'plugin:cypress/recommended',
  ],
  parser: 'babel-eslint',
  parserOptions: {
    ecmaVersion: 2018,
    sourceType: 'module',
    ecmaFeatures: {
      jsx: true,
    },
  },
  settings: {
    react: {
      version: 'detect',
    },
    'import/resolver': {
      node: {
        extensions: ['.js', '.jsx', '.ts', '.tsx'],
      },
    },
  },
  env: {
    browser: true,
    commonjs: true,
    es6: true,
    jest: true,
    node: true,
  },
  overrides: [
    {
      files: ['**/*.ts?(x)'],
      plugins: ['@typescript-eslint'],
      extends: [
        'plugin:@typescript-eslint/eslint-recommended',
        'prettier/@typescript-eslint',
        'plugin:import/typescript',
      ],
      parser: '@typescript-eslint/parser',
      parserOptions: {
        warnOnUnsupportedTypeScriptVersion: true,
      },
      rules: {
        // APIs are not camelCase
        '@typescript-eslint/camelcase': 'off',
        camelcase: 'off',
        // Use TypeScript types instead
        'react/prop-types': 'off',
        // Fixes definition files imports
        'spaced-comment': ['error', 'always', { markers: ['/'] }],
        'react/jsx-filename-extension': ['error', { extensions: ['.tsx'] }],
        // https://github.com/typescript-eslint/typescript-eslint/blob/master/packages/eslint-plugin/docs/rules/no-unused-vars.md
        'no-unused-vars': 'off',
        '@typescript-eslint/no-unused-vars': ['warn'],
        // https://github.com/typescript-eslint/typescript-eslint/blob/master/packages/eslint-plugin/docs/rules/no-unused-expressions.md
        'no-unused-expressions': 'off',
        '@typescript-eslint/no-unused-expressions': [
          'error',
          { allowShortCircuit: true },
        ],
        'react/destructuring-assignment': ['error', 'never'],
      },
    },
    {
      files: ['**/*.{spec,test}.{js,jsx,ts,tsx}'],
      rules: {
        'max-lines-per-function': 'off',
        complexity: 'off',
      },
    },
  ],
  rules: {
    // START :: DO NOT TOUCH THESE, these need to be in sync with `core-prettier`
    'prettier/prettier': 'error',
    curly: ['error', 'all'],
    'lines-around-comment': [
      'error',
      {
        // https://github.com/typescript-eslint/typescript-eslint/issues/1150
        beforeBlockComment: false,
        afterBlockComment: false,
        // https://github.com/typescript-eslint/typescript-eslint/issues/1150
        beforeLineComment: false,
        afterLineComment: false,
        allowBlockStart: true,
        allowBlockEnd: false,
        allowObjectStart: true,
        allowObjectEnd: false,
        allowArrayStart: true,
        allowArrayEnd: false,
        allowClassStart: true,
        allowClassEnd: false,
      },
    ],
    'max-len': [
      'warn',
      {
        code: 80,
        ignoreUrls: true,
        ignoreStrings: true,
        ignoreTemplateLiterals: true,
        ignoreTrailingComments: true,
      },
    ],
    'no-confusing-arrow': ['error', { allowParens: true }],
    'no-mixed-operators': 'error',
    'no-tabs': 'error',
    'no-unexpected-multiline': 'error',
    quotes: [
      'error',
      'single',
      { avoidEscape: true, allowTemplateLiterals: false },
    ],
    // END :: DO NOT TOUCH THESE, these need to be in sync with `core-prettier`
    'import/prefer-default-export': 'off',
    'react/destructuring-assignment': ['error', 'always'],
    'import/no-extraneous-dependencies': [
      'error',
      {
        devDependencies: [
          '**/*.@(spec|test|story|stories).@(js|jsx|ts|tsx)',
          '**/__tests__/**',
          '**/.storybook/**',
          '**/e2e/**',
        ],
        peerDependencies: true,
      },
    ],
    'no-param-reassign': [
      'error',
      { props: true, ignorePropertyModificationsFor: ['self'] },
    ],
    'react/jsx-props-no-spreading': 'off',
    'react/jsx-fragments': ['error', 'syntax'],
    'import/no-unresolved': ['error', { ignore: ['^@'] }], // webpack alias for 'src' - from core-scripts
    'import/extensions': [
      'error',
      'ignorePackages',
      {
        js: 'never',
        mjs: 'never',
        jsx: 'never',
        tsx: 'never',
        ts: 'never',
      },
    ],
    'react-hooks/exhaustive-deps': 'off',
    'no-use-before-define': ['error', { functions: false }],
    'no-plusplus': ['error', { allowForLoopAfterthoughts: true }],
    'no-unused-expressions': ['error', { allowShortCircuit: true }],
    'max-lines-per-function': ['error', { max: 150 }],
    complexity: ['error', { max: 10 }],
    'lines-between-class-members': [
      'error',
      'always',
      {
        exceptAfterSingleLine: true,
      },
    ],
  },
}