.eslintrc.cjs

module.exports = {
  root: true,
  env: {
    browser: true,
    es6: true,
    node: true,
    mocha: true,
  },
  globals: {
    BigInt: true,
  },
  parser: '@typescript-eslint/parser',
  parserOptions: {
    ecmaVersion: 10,
    project: './tsconfig.json',
    sourceType: 'module',
  },
  plugins: ['@typescript-eslint', 'eslint-plugin-import', '@chainsafe/eslint-plugin-node', 'prettier'],
  extends: [
    'eslint:recommended',
    'plugin:@typescript-eslint/recommended',
    'plugin:import/errors',
    'plugin:import/typescript',
    'plugin:import/warnings',
  ],
  rules: {
    '@chainsafe/node/file-extension-in-import': ['error', 'always', { esm: true }],
    '@chainsafe/node/no-deprecated-api': 'error',
    '@typescript-eslint/await-thenable': 'error',
    '@typescript-eslint/ban-ts-comment': 'error',
    '@typescript-eslint/explicit-function-return-type': ['error', { allowExpressions: true }],
    '@typescript-eslint/explicit-member-accessibility': ['error', { accessibility: 'no-public' }],
    '@typescript-eslint/func-call-spacing': 'error',
    // TODO after upgrading es-lint, member-ordering is now leading to lint errors. Set to warning now and fix in another PR
    '@typescript-eslint/member-ordering': 'off',
    '@typescript-eslint/naming-convention': [
      'error',
      { selector: 'default', format: ['camelCase'] },
      {
        selector: ['classProperty', 'objectLiteralProperty', 'classMethod', 'parameter'],
        format: ['camelCase'],
        leadingUnderscore: 'allow',
      },
      //variable must be in camel or upper case
      { selector: 'variable', format: ['camelCase', 'UPPER_CASE'], leadingUnderscore: 'allow' },
      //classes and types must be in PascalCase
      { selector: ['typeLike', 'enum'], format: ['PascalCase'] },
      { selector: 'enumMember', format: null },
      //ignore rule for quoted stuff
      {
        selector: [
          'classProperty',
          'objectLiteralProperty',
          'typeProperty',
          'classMethod',
          'objectLiteralMethod',
          'typeMethod',
          'accessor',
          'enumMember',
        ],
        format: null,
        modifiers: ['requiresQuotes'],
      },
      //ignore rules on destructured params
      { selector: 'variable', modifiers: ['destructured'], format: null },
    ],
    '@typescript-eslint/no-explicit-any': 'error',
    '@typescript-eslint/no-floating-promises': 'error',
    '@typescript-eslint/no-non-null-assertion': 'error',
    '@typescript-eslint/no-require-imports': 'error',
    // We usually type-cast these standard types because the concerned function accepts any type
    // and we want to TS detect error if original variable type changes
    '@typescript-eslint/no-unnecessary-type-assertion': ['error', { typesToIgnore: ['string', 'bigint', 'number'] }],
    '@typescript-eslint/no-unsafe-assignment': 'error',
    '@typescript-eslint/no-unsafe-call': 'error',
    '@typescript-eslint/no-unsafe-member-access': 'error',
    '@typescript-eslint/no-unsafe-return': 'error',
    '@typescript-eslint/no-unused-vars': ['error', { varsIgnorePattern: '^_', argsIgnorePattern: '^_' }],
    '@typescript-eslint/no-use-before-define': 'off',
    '@typescript-eslint/restrict-template-expressions': [
      'error',
      { allowNumber: true, allowBoolean: true, allowNullish: true, allowNever: true, allowRegExp: true },
    ],
    '@typescript-eslint/return-await': 'error',
    '@typescript-eslint/semi': 'error',
    '@typescript-eslint/strict-boolean-expressions': [
      'error',
      { allowNullableBoolean: true, allowNullableString: true, allowAny: true },
    ],

    '@typescript-eslint/type-annotation-spacing': 'error',
    'constructor-super': 'off',
    'func-call-spacing': 'off',
    // Force to add names to all functions to ease CPU profiling
    'func-names': ['error', 'always'],
    //if --fix is run it messes imports like /lib/presets/minimal & /lib/presets/mainnet
    'import/no-duplicates': 'off',
    'import/no-extraneous-dependencies': [
      'error',
      {
        devDependencies: false,
        optionalDependencies: false,
        peerDependencies: false,
      },
    ],
    'import/no-relative-packages': 'error',
    // TEMP Disabled while eslint-plugin-import support ESM (Typescript does support it) https://github.com/import-js/eslint-plugin-import/issues/2170
    'import/no-unresolved': 'off',
    'import/order': [
      'error',
      {
        groups: ['builtin', 'external', 'internal', 'parent', 'sibling', 'index'],
        pathGroups: [{ pattern: '@lodestar/**', group: 'internal' }],
        pathGroupsExcludedImportTypes: ['builtin'],
      },
    ],
    //doesnt work, it reports false errors
    'new-parens': 'error',
    'no-bitwise': 'off',
    'no-caller': 'error',
    'no-cond-assign': 'error',
    'no-consecutive-blank-lines': 0,
    'no-console': 'error',
    'no-loss-of-precision': 'error',
    'no-prototype-builtins': 0,
    'no-restricted-imports': [
      'error',
      {
        patterns: ['../lib/*', '@chainsafe/*/lib/*'],
        paths: [
          ...restrictNodeModuleImports(
            'child_process',
            'crypto',
            'fs',
            'http',
            'net',
            'os',
            'path',
            'stream',
            'util',
            'url',
            'worker_threads',
          ),
        ],
      },
    ],
    'no-restricted-syntax': ['error', ...restrictImportDestructuring('node:fs', 'node:os', 'node:path')],
    // superseded by @typescript-eslint/return-await, must be disabled as it can report incorrect errors
    'no-return-await': 'off',
    'no-var': 'error',
    'object-curly-spacing': ['error', 'never'],
    'object-literal-sort-keys': 0,
    'prefer-const': 'error',
    'prettier/prettier': 'error',
    quotes: ['error', 'double'],
    semi: 'off',
  },
  settings: {
    'import/core-modules': [
      'node:child_process',
      'node:crypto',
      'node:fs',
      'node:http',
      'node:net',
      'node:os',
      'node:path',
      'node:stream',
      'node:util',
      'node:url',
    ],
    'import/resolver': {
      typescript: {
        project: 'packages/*/tsconfig.json',
      },
    },
  },
  overrides: [
    {
      files: ['**/*.config.js', '**/*.config.mjs', '**/*.config.cjs', '**/*.config.ts'],
      rules: {
        '@typescript-eslint/naming-convention': 'off',
        // Allow require in CJS modules
        '@typescript-eslint/no-require-imports': 'off',
        // Allow require in CJS modules
        '@typescript-eslint/no-var-requires': 'off',
        // Allow importing packages from dev dependencies
        'import/no-extraneous-dependencies': 'off',
        // Allow importing and mixing different configurations
        'import/no-relative-packages': 'off',
      },
    },
    {
      files: ['**/test/**/*.ts'],
      rules: {
        '@typescript-eslint/no-explicit-any': 'off',
        'func-names': 'off',
        'import/no-extraneous-dependencies': 'off',
        // Turned off as it floods log with warnings. Underlying issue is not critical so switching off is acceptable
        'import/no-named-as-default-member': 'off',
      },
    },
    {
      files: ['**/test/**/*.test.ts'],
      plugins: ['mocha', 'chai-expect'],
      extends: ['plugin:mocha/recommended', 'plugin:chai-expect/recommended'],
      rules: {
        // We observed that having multiple top level "describe" save valuable indentation
        // https://github.com/lo1tuma/eslint-plugin-mocha/blob/master/docs/rules/max-top-level-suites.md
        'mocha/max-top-level-suites': 'off',
        // We need to disable because we disabled "mocha/no-setup-in-describe" rule
        // TODO: Move all setup code to before/beforeEach and then disable async describe
        // https://github.com/lo1tuma/eslint-plugin-mocha/blob/master/docs/rules/no-async-describe.md
        'mocha/no-async-describe': 'off',
        // Use of arrow functions are very common
        'mocha/no-mocha-arrows': 'off',
        // It's common to call function inside describe block
        // https://github.com/lo1tuma/eslint-plugin-mocha/blob/master/docs/rules/no-setup-in-describe.md
        'mocha/no-setup-in-describe': 'off',
        // We use to split before in small isolated tasks
        // https://github.com/lo1tuma/eslint-plugin-mocha/blob/master/docs/rules/no-sibling-hooks.md
        'mocha/no-sibling-hooks': 'off',
      },
    },
    {
      files: ['**/types/**/*.ts'],
      rules: {
        '@typescript-eslint/naming-convention': [
          'off',
          { selector: 'interface', prefix: ['I'] },
          { selector: 'interface', format: ['PascalCase'], prefix: ['I'] },
        ],
      },
    },
  ],
};

function restrictNodeModuleImports(...modules) {
  return modules.map((module) => ({ name: module, message: `Please use 'node:${module}' instead.` }));
}

function restrictImportDestructuring(...modules) {
  return modules.map((module) => ({
    selector: `ImportDeclaration[source.value='${module}'] ImportSpecifier`,
    message: `Importing from '${module}' using destructuring is restricted.`,
  }));
}