.eslintrc.js

// @ts-check
const { defineConfig } = require('eslint-define-config');
const { readGitignoreFiles } = require('eslint-gitignore');

module.exports = defineConfig({
  ignorePatterns: [
    ...readGitignoreFiles(),
    '.eslintrc.js', // Skip self linting
  ],
  root: true,
  env: {
    browser: true,
    node: true,
  },
  reportUnusedDisableDirectives: true,
  extends: [
    'eslint:recommended',
    'plugin:@typescript-eslint/recommended',
    'plugin:@typescript-eslint/recommended-requiring-type-checking',
    'plugin:prettier/recommended',
  ],
  parser: '@typescript-eslint/parser',
  parserOptions: {
    project: ['./tsconfig.lint.json'],
    sourceType: 'module',
    warnOnUnsupportedTypeScriptVersion: false,
  },
  plugins: ['@typescript-eslint', 'prettier', 'deprecation'],
  rules: {
    // We may want to use this in the future
    'no-useless-escape': 'off',
    eqeqeq: ['error', 'always', { null: 'ignore' }],
    'no-else-return': 'error',
    'prefer-template': 'error',

    'deprecation/deprecation': 'error',

    '@typescript-eslint/array-type': [
      'error',
      { default: 'array-simple', readonly: 'generic' },
    ],
    '@typescript-eslint/ban-ts-comment': 'error',
    '@typescript-eslint/consistent-type-imports': 'error',
    '@typescript-eslint/explicit-module-boundary-types': 'error',
    '@typescript-eslint/naming-convention': [
      'error',
      {
        format: ['PascalCase'],
        selector: ['class', 'interface', 'typeAlias', 'enumMember'],
        leadingUnderscore: 'forbid',
        trailingUnderscore: 'forbid',
      },
      {
        format: ['PascalCase'],
        selector: ['typeParameter'],
        prefix: ['T'],
        leadingUnderscore: 'forbid',
        trailingUnderscore: 'forbid',
      },
    ],
    '@typescript-eslint/no-inferrable-types': [
      'error',
      { ignoreParameters: true },
    ],
    '@typescript-eslint/no-unsafe-argument': 'error',
    '@typescript-eslint/no-unsafe-assignment': 'off',
    '@typescript-eslint/no-unsafe-call': 'off',
    '@typescript-eslint/no-unsafe-member-access': 'off',
    '@typescript-eslint/no-unsafe-return': 'error',
    '@typescript-eslint/padding-line-between-statements': [
      'error',
      { blankLine: 'always', prev: 'block-like', next: '*' },
    ],
    '@typescript-eslint/restrict-template-expressions': [
      'error',
      { allowNumber: true, allowBoolean: true },
    ],
    '@typescript-eslint/unbound-method': 'off',
  },
  overrides: [
    {
      files: ['src/**/*.ts'],
      plugins: ['jsdoc'],
      extends: ['plugin:jsdoc/recommended-error'],
      rules: {
        'jsdoc/no-types': 'error',
        'jsdoc/require-param-type': 'off',
        'jsdoc/require-returns-type': 'off',
        'jsdoc/require-returns': 'off',
        'jsdoc/tag-lines': 'off',
        'jsdoc/sort-tags': [
          'error',
          {
            tagSequence: [
              { tags: ['template'] },
              { tags: ['internal'] },
              { tags: ['param'] },
              { tags: ['returns'] },
              { tags: ['throws'] },
              { tags: ['see'] },
              { tags: ['example'] },
              { tags: ['since'] },
              { tags: ['default'] },
              { tags: ['deprecated'] },
            ],
          },
        ],
      },
      settings: {
        jsdoc: {
          mode: 'typescript',
        },
      },
    },
    {
      files: ['test/*.spec.ts'],
      extends: ['plugin:vitest/recommended'],
      rules: {
        'deprecation/deprecation': 'off',

        '@typescript-eslint/restrict-template-expressions': [
          'error',
          {
            allowNumber: true,
            allowBoolean: true,
            allowAny: true,
          },
        ],

        'vitest/expect-expect': 'off',
        'vitest/prefer-each': 'error',
        'vitest/valid-expect': ['error', { maxArgs: 2 }],
      },
    },
  ],
});