const rulesDirPlugin = require('eslint-plugin-rulesdir'); rulesDirPlugin.RULES_DIR = 'tools/eslint/lib'; module.exports = { root: true, env: { node: true, es6: true, }, parser: '@typescript-eslint/parser', plugins: ['mocha', '@typescript-eslint', 'import'], extends: ['plugin:prettier/recommended', 'plugin:import/typescript'], settings: { 'import/resolver': { typescript: true, }, }, rules: { // Brackets keep code readable. curly: ['error', 'all'], // Brackets keep code readable and `return` intentions clear. 'arrow-body-style': ['error', 'always'], // Error if files are not formatted with Prettier correctly. 'prettier/prettier': 'error', // syntax preferences 'spaced-comment': [ 'error', 'always', { markers: ['*'], }, ], eqeqeq: ['error'], 'accessor-pairs': [ 'error', { getWithoutSet: false, setWithoutGet: false, }, ], 'new-parens': 'error', 'func-call-spacing': 'error', 'prefer-const': 'error', 'max-len': [ 'error', { /* 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': 'error', 'no-with': 'error', 'no-multi-str': 'error', 'no-caller': 'error', 'no-implied-eval': 'error', 'no-labels': 'error', 'no-new-object': 'error', 'no-octal-escape': 'error', 'no-self-compare': 'error', 'no-shadow-restricted-names': 'error', 'no-cond-assign': 'error', 'no-debugger': 'error', 'no-dupe-keys': 'error', 'no-duplicate-case': 'error', 'no-empty-character-class': 'error', 'no-unreachable': 'error', 'no-unsafe-negation': 'error', radix: 'error', 'valid-typeof': 'error', 'no-unused-vars': [ 'error', { args: 'none', vars: 'local', varsIgnorePattern: '([fx]?describe|[fx]?it|beforeAll|beforeEach|afterAll|afterEach)', }, ], 'no-implicit-globals': ['error'], // es2015 features 'require-yield': 'error', 'template-curly-spacing': ['error', 'never'], // ensure we don't have any it.only or describe.only in prod 'mocha/no-exclusive-tests': 'error', 'no-restricted-imports': [ 'error', { patterns: ['*Events', '*.test.js'], paths: [ { name: 'mitt', message: 'Import `mitt` from the vendored location: third_party/mitt/index.js', }, ], }, ], 'import/order': [ 'error', { 'newlines-between': 'always', alphabetize: {order: 'asc', caseInsensitive: true}, }, ], 'import/no-cycle': ['warn', {maxDepth: Infinity}], 'no-restricted-syntax': [ 'error', // Don't allow underscored declarations on camelCased variables/properties. // ...RESTRICTED_UNDERSCORED_IDENTIFIERS, ], }, overrides: [ { files: ['*.ts'], parserOptions: { allowAutomaticSingleRunInference: true, project: './tsconfig.base.json', }, extends: [ 'plugin:@typescript-eslint/eslint-recommended', 'plugin:@typescript-eslint/recommended', 'plugin:@typescript-eslint/stylistic', ], plugins: ['eslint-plugin-tsdoc', 'rulesdir'], rules: { // Keeps comments formatted. 'rulesdir/prettier-comments': 'error', // Enforces clean up of used resources. 'rulesdir/use-using': 'error', // Brackets keep code readable. curly: ['error', 'all'], // Brackets keep code readable and `return` intentions clear. 'arrow-body-style': ['error', 'always'], // Error if comments do not adhere to `tsdoc`. 'tsdoc/syntax': 'error', // Keeps array types simple only when they are simple for readability. '@typescript-eslint/array-type': ['error', {default: 'array-simple'}], 'no-unused-vars': 'off', '@typescript-eslint/no-unused-vars': [ 'error', {argsIgnorePattern: '^_', varsIgnorePattern: '^_'}, ], 'func-call-spacing': 'off', '@typescript-eslint/func-call-spacing': 'error', semi: 'off', '@typescript-eslint/semi': 'error', '@typescript-eslint/no-empty-function': 'off', '@typescript-eslint/no-use-before-define': 'off', // We have to use any on some types so the warning isn't valuable. '@typescript-eslint/no-explicit-any': 'off', // We don't require explicit return types on basic functions or // dummy functions in tests, for example '@typescript-eslint/explicit-function-return-type': 'off', // We allow non-null assertions if the value was asserted using `assert` API. '@typescript-eslint/no-non-null-assertion': 'off', /** * This is the default options (as per * https://github.com/typescript-eslint/typescript-eslint/blob/HEAD/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, }, }, ], // By default this is a warning but we want it to error. '@typescript-eslint/explicit-module-boundary-types': 'error', 'no-restricted-syntax': [ 'error', { // Never use `require` in TypeScript since they are transpiled out. selector: "CallExpression[callee.name='require']", message: '`require` statements are not allowed. Use `import`.', }, { // We need this as NodeJS will run until all the timers have resolved message: 'Use method `Deferred.race()` instead.', selector: 'MemberExpression[object.name="Promise"][property.name="race"]', }, { message: 'Deferred `valueOrThrow` should not be called in `Deferred.race()` pass deferred directly', selector: 'CallExpression[callee.object.name="Deferred"][callee.property.name="race"] > ArrayExpression > CallExpression[callee.property.name="valueOrThrow"]', }, ], '@typescript-eslint/no-floating-promises': [ 'error', {ignoreVoid: true, ignoreIIFE: true}, ], '@typescript-eslint/prefer-ts-expect-error': 'error', // This is more performant; see https://v8.dev/blog/fast-async. '@typescript-eslint/return-await': ['error', 'always'], // This optimizes the dependency tracking for type-only files. '@typescript-eslint/consistent-type-imports': [ 'error', { disallowTypeAnnotations: false, fixStyle: 'inline-type-imports', }, ], }, overrides: [ { files: [ 'packages/puppeteer-core/src/**/*.test.ts', 'tools/mocha-runner/src/test.ts', ], rules: { // With the Node.js test runner, `describe` and `it` are technically // promises, but we don't need to await them. '@typescript-eslint/no-floating-promises': 'off', }, }, ], }, ], };