@awesome-code-style/eslint-config/index.js

ESLint configuration for TypeScript projects that might use React

import js from '@eslint/js';
import stylistic from '@stylistic/eslint-plugin';
import prettier from 'eslint-config-prettier';
import importPlugin from 'eslint-plugin-import';
import simpleImportSortPlugin from 'eslint-plugin-simple-import-sort';
import unusedImportsPlugin from 'eslint-plugin-unused-imports';
import tseslint from 'typescript-eslint';

export const configs = {
  default: [
    js.configs.recommended,
    ...tseslint.configs.recommended,
    ...tseslint.configs.stylistic,
    prettier,
    {
      plugins: {
        '@stylistic': stylistic,
        'import': importPlugin,
        'simple-import-sort': simpleImportSortPlugin,
        'unused-imports': unusedImportsPlugin,
      },

      rules: {
        // eslint (adds)
        'eqeqeq': ['error', 'smart'],
        'max-classes-per-file': ['error', 1],
        'no-bitwise': 'error',
        'no-caller': 'error',
        'no-eval': 'error',
        'no-new-wrappers': 'error',
        'no-throw-literal': 'error',
        'no-undef-init': 'error',
        'one-var': ['error', 'never'],
        'prefer-object-spread': 'warn',
        'radix': 'error',

        // eslint (overrides)
        'no-empty': 'off',
        'no-fallthrough': 'off',
        'prefer-const': ['error', { destructuring: 'all' }],

        // @typescript-eslint (adds)
        '@typescript-eslint/ban-tslint-comment': 'error',
        '@typescript-eslint/consistent-type-assertions': 'error',
        '@typescript-eslint/consistent-type-imports': ['warn', { prefer: 'type-imports' }],
        '@typescript-eslint/member-ordering': 'off', // TODO: use?
        '@typescript-eslint/no-confusing-non-null-assertion': 'error',
        '@typescript-eslint/no-shadow': ['off', { ignoreTypeValueShadow: true }], // TODO: use?
        '@typescript-eslint/no-unnecessary-type-constraint': 'warn',
        '@typescript-eslint/no-unused-expressions': 'error',
        '@typescript-eslint/prefer-function-type': 'error',
        '@typescript-eslint/unified-signatures': 'error',

        // @typescript-eslint (overrides)
        '@typescript-eslint/consistent-indexed-object-style': 'off',
        '@typescript-eslint/consistent-type-definitions': 'off',
        '@typescript-eslint/explicit-module-boundary-types': 'off',
        '@typescript-eslint/no-empty-function': 'off',
        '@typescript-eslint/no-empty-object-type': [
          'error',
          { allowInterfaces: 'with-single-extends' },
        ],
        '@typescript-eslint/no-explicit-any': 'off',
        '@typescript-eslint/no-non-null-assertion': 'off',
        '@typescript-eslint/no-this-alias': 'off',
        '@typescript-eslint/no-unused-vars': 'off',
        '@typescript-eslint/prefer-for-of': 'off',

        // @stylistic (adds)
        '@stylistic/no-multiple-empty-lines': ['error', { max: 2 }],
        '@stylistic/spaced-comment': ['error', 'always', { markers: ['/'] }],
        '@stylistic/lines-between-class-members': [
          'warn',
          'always',
          { exceptAfterSingleLine: true },
        ],
        '@stylistic/padding-line-between-statements': [
          'warn',

          { blankLine: 'always', prev: '*', next: 'interface' },
          { blankLine: 'always', prev: 'interface', next: '*' },

          { blankLine: 'always', prev: '*', next: 'function' },
          { blankLine: 'always', prev: 'function', next: '*' },
        ],

        // eslint-plugin-simple-import-sort, eslint-plugin-import
        'simple-import-sort/imports': [
          'error',
          {
            groups: [
              // Side effect imports (except (s)css files)
              ['^\\u0000(?!.+.s?css)'],
              // Packages.
              // Things that start with a letter (or digit or underscore), or `@` followed by a letter.
              ['^@?\\w'],
              // Absolute imports and other imports such as Vue-style `@/foo`.
              // Anything not matched in another group.
              ['^'],
              // Relative parent imports.
              // Anything that starts with two dots.
              ['^\\.\\.'],
              // Relative local imports.
              // Anything that starts with one dot.
              ['^\\.'],
              // (s)css imports
              ['^\\u0000.+.s?css$'],
            ],
          },
        ],
        'simple-import-sort/exports': 'error',
        'import/first': 'error',
        'import/newline-after-import': 'error',
        'import/no-duplicates': 'error',
        'import/no-extraneous-dependencies': 'error',

        // eslint-plugin-unused-imports
        'unused-imports/no-unused-imports': 'error',
        'unused-imports/no-unused-vars': [
          'warn',
          {
            vars: 'all',
            varsIgnorePattern: '^_',
            args: 'after-used',
            argsIgnorePattern: '^_',
            caughtErrorsIgnorePattern: '(^_)|(^e$)',
          },
        ],
      },
    },
  ],

  typeChecked: [
    ...tseslint.configs.recommendedTypeCheckedOnly,
    ...tseslint.configs.stylisticTypeCheckedOnly,
    {
      languageOptions: {
        parserOptions: {
          // https://typescript-eslint.io/packages/parser#projectservice
          projectService: true,
        },
      },
      rules: {
        // @typescript-eslint (adds)
        '@typescript-eslint/naming-convention': 'off', // TODO: use?
        '@typescript-eslint/no-confusing-void-expression': [
          'error',
          { ignoreArrowShorthand: true },
        ],
        '@typescript-eslint/no-unnecessary-boolean-literal-compare': 'warn',
        '@typescript-eslint/no-unnecessary-qualifier': 'warn',
        '@typescript-eslint/no-unnecessary-type-arguments': 'warn',
        '@typescript-eslint/non-nullable-type-assertion-style': 'warn',
        '@typescript-eslint/prefer-includes': 'warn',
        '@typescript-eslint/prefer-readonly': 'warn',
        '@typescript-eslint/prefer-reduce-type-parameter': 'warn',
        '@typescript-eslint/prefer-string-starts-ends-with': 'warn',
        '@typescript-eslint/switch-exhaustiveness-check': 'error',

        // @typescript-eslint (overrides)
        '@typescript-eslint/dot-notation': 'off',
        '@typescript-eslint/no-base-to-string': 'off',
        '@typescript-eslint/no-unsafe-argument': 'off', // TODO: use?
        '@typescript-eslint/no-unsafe-assignment': 'off', // TODO: use?
        '@typescript-eslint/no-unsafe-call': 'off', // TODO: use?
        '@typescript-eslint/no-unsafe-member-access': 'off', // TODO: use?
        '@typescript-eslint/no-unsafe-return': 'off', // TODO: use?
        '@typescript-eslint/prefer-nullish-coalescing': 'off',
        '@typescript-eslint/prefer-optional-chain': 'off',
        '@typescript-eslint/restrict-plus-operands': 'off',
        '@typescript-eslint/restrict-template-expressions': 'off',
        '@typescript-eslint/unbound-method': 'off',
      },
    },
  ],

  disableTypeChecked: tseslint.configs.disableTypeChecked,
};

export default configs.default;