Perfective ESLint Config

@perfective/eslint-config provides a shareable ESLint configuration that is used for the development of the @perfective packages. These rules are primarily configured for TypeScript projects.

In addition to the core ESLint, @typescript-eslint, and ESLint Stylistic plugin rules, @perfective/eslint-config includes configurations for the ESLint plugins:

eslint-plugin-array-func;
eslint-plugin-cypress (optional);
@eslint-community/eslint-plugin-eslint-comments;
eslint-plugin-import;
eslint-plugin-jest (optional);
eslint-plugin-jest-dom (optional);
eslint-plugin-jsdoc;
eslint-plugin-n;
eslint-plugin-prefer-arrow;
eslint-plugin-promise;
eslint-plugin-rxjs-x (optional);
eslint-plugin-security;
eslint-plugin-simple-import-sort;
eslint-plugin-testing-library (optional);
eslint-plugin-unicorn.

To simplify configuring ESLint support in the IDEs and editors, the severity of all fixable rules is a warning. In addition, it allows distinguishing errors that have to be fixed manually from issues that will be fixed automatically.

Setup

Important

@perfective/eslint-config only support ES module syntax. If your project uses CommonJS by default you need to use eslint.config.mjs file instead of eslint.config.js to run it in ESM mode.

Install @perfective/eslint-config as a dev dependency:
```
npm install --save-dev @perfective/eslint-config
```
Required peer dependencies are installed automatically.

Import perfectiveEslintConfig to eslint.config.js.

import { perfectiveEslintConfig } from '@perfective/eslint-config';

const eslintConfig = perfectiveEslintConfig();

export default eslintConfig;

Optional Install optional peer dependencies to add tool-specific linting rules.

npm install --save-dev \
    eslint-plugin-cypress \
    eslint-plugin-jest \
    eslint-plugin-jest-dom \
    eslint-plugin-rxjs-x \
    eslint-plugin-testing-library

Import configurations to eslint.config.js.

import { perfectiveEslintConfig } from '@perfective/eslint-config';

// Optional dependencies.
import { cypressConfig } from '@perfective/eslint-config/cypress';
import { jestConfig } from '@perfective/eslint-config/jest';
import { jestDomConfig } from '@perfective/eslint-config/jest-dom';
import { rxjsConfig } from '@perfective/eslint-config/rxjs';
import { testingLibraryConfig } from '@perfective/eslint-config/testing-library';

const eslintConfig = perfectiveEslintConfig([
    cypressConfig,
    jestConfig,
    jestDomConfig,
    rxjsConfig,
    testingLibraryConfig,
]);

export default eslintConfig;

Optional Customize configuration rules in eslint.config.js

import { perfectiveEslintConfig, typescriptFiles } from '@perfective/eslint-config'; // (1)

const eslintConfig = perfectiveEslintConfig([
    // ...Optional configurations...
    {
        // These rules are overridden to all files
        rules: {
            '@stylistic/indent': ['warn', 2],
        },
    },
    {
        // These rules are overridden to TypeScript files only
        files: typescriptFiles,
        rules: {
            '@stylistic/indent': ['warn', 4],
        },
    },
]);

export default eslintConfig;

See the list of available globs below.

Note	`*.d.ts` files and `dist` directories are ignored by the configuration. `node_modules` and dot-files are ignored by the `eslint`. If more directories or file types need to be ignored, see the `.eslintignore` file docs.

Rules configuration functions

Some rules have complex configuration objects or arrays that are not merged but are completely overridden by ESLint. Therefore, it requires copying and pasting a rule config instead of just extending it. Maintaining rules updates is challenging and is simplified by the custom config functions.

These functions and related types are exported from the subpackages and match the rule name in camelCase. If you need an extended configuration, you can use these functions in the eslint.config.js file:

import perfectiveEslintConfig from '@perfective/eslint-config';
import { simpleImportSortImports } from '@perfective/eslint-config/simple-import-sort'; // (1)

const eslintConfig = perfectiveEslintConfig([
    // ...Optional configurations...
    {
        rules: {
            'simple-import-sort/imports': ['warn', simpleImportSortImports([
                '@perfective',
            ])],
        },
    },
]);

export default eslintConfig;

Framework-specific packages, based on @perfective/eslint-config, re-export all the rules. So rules should be required from those packages for correct node_modules resolution.

Packages [#packages]

The following is the list of available packages and their exports.