module.exports = { root: true, env: { node: true, es6: true, }, parser: '@typescript-eslint/parser', plugins: ['mocha', '@typescript-eslint', 'unicorn', 'import'], extends: ['plugin:prettier/recommended'], rules: { // Error if files are not formatted with Prettier correctly. 'prettier/prettier': 2, // syntax preferences quotes: [ 2, 'single', { avoidEscape: true, allowTemplateLiterals: true, }, ], 'spaced-comment': [ 2, 'always', { markers: ['*'], }, ], eqeqeq: [2], 'accessor-pairs': [ 2, { getWithoutSet: false, setWithoutGet: false, }, ], 'new-parens': 2, 'func-call-spacing': 2, 'prefer-const': 2, 'max-len': [ 2, { /* this setting doesn't impact things as we use Prettier to format * our code and hence dictate the line length. * Prettier aims for 80 but sometimes makes the decision to go just * over 80 chars as it decides that's better than wrapping. ESLint's * rule defaults to 80 but therefore conflicts with Prettier. So we * set it to something far higher than Prettier would allow to avoid * it causing issues and conflicting with Prettier. */ code: 200, comments: 90, ignoreTemplateLiterals: true, ignoreUrls: true, ignoreStrings: true, ignoreRegExpLiterals: true, }, ], // anti-patterns 'no-var': 2, 'no-with': 2, 'no-multi-str': 2, 'no-caller': 2, 'no-implied-eval': 2, 'no-labels': 2, 'no-new-object': 2, 'no-octal-escape': 2, 'no-self-compare': 2, 'no-shadow-restricted-names': 2, 'no-cond-assign': 2, 'no-debugger': 2, 'no-dupe-keys': 2, 'no-duplicate-case': 2, 'no-empty-character-class': 2, 'no-unreachable': 2, 'no-unsafe-negation': 2, radix: 2, 'valid-typeof': 2, 'no-unused-vars': [ 2, { args: 'none', vars: 'local', varsIgnorePattern: '([fx]?describe|[fx]?it|beforeAll|beforeEach|afterAll|afterEach)', }, ], 'no-implicit-globals': [2], // es2015 features 'require-yield': 2, 'template-curly-spacing': [2, 'never'], // ensure we don't have any it.only or describe.only in prod 'mocha/no-exclusive-tests': 'error', // enforce the variable in a catch block is named error 'unicorn/catch-error-name': 'error', 'no-restricted-imports': [ 'error', { patterns: ['*Events'], paths: [ { name: 'mitt', message: 'Import Mitt from the vendored location: vendor/mitt/src/index.js', }, ], }, ], 'import/extensions': ['error', 'ignorePackages'], }, overrides: [ { files: ['*.ts'], extends: [ 'plugin:@typescript-eslint/eslint-recommended', 'plugin:@typescript-eslint/recommended', ], rules: { 'no-unused-vars': 0, '@typescript-eslint/no-unused-vars': 2, 'func-call-spacing': 0, '@typescript-eslint/func-call-spacing': 2, semi: 0, '@typescript-eslint/semi': 2, '@typescript-eslint/no-empty-function': 0, '@typescript-eslint/no-use-before-define': 0, // We have to use any on some types so the warning isn't valuable. '@typescript-eslint/no-explicit-any': 0, // We don't require explicit return types on basic functions or // dummy functions in tests, for example '@typescript-eslint/explicit-function-return-type': 0, // We know it's bad and use it very sparingly but it's needed :( '@typescript-eslint/ban-ts-ignore': 0, /** * This is the default options (as per * https://github.com/typescript-eslint/typescript-eslint/blob/master/packages/eslint-plugin/docs/rules/ban-types.md), * * Unfortunately there's no way to */ '@typescript-eslint/ban-types': [ 'error', { extendDefaults: true, types: { /* * Puppeteer's API accepts generic functions in many places so it's * not a useful linting rule to ban the `Function` type. This turns off * the banning of the `Function` type which is a default rule. */ Function: false, }, }, ], '@typescript-eslint/array-type': [ 2, { default: 'array-simple', }, ], }, }, { files: ['test-browser/**/*.js'], parserOptions: { sourceType: 'module', }, env: { es6: true, browser: true, es2020: true, }, }, ], };