# How to Lint TypeScript Code with ESLint in the iptv-org/iptv Repository > Learn how to lint TypeScript code with ESLint in the iptv-org/iptv repository. Discover the configuration and benefits of enforcing code quality and style. - Repository: [iptv-org/iptv](https://github.com/iptv-org/iptv) - Tags: how-to-guide - Published: 2026-02-25 --- **The iptv-org/iptv repository uses ESLint with @typescript-eslint and @stylistic plugins configured in `eslint.config.mjs` to enforce code quality and consistent style across TypeScript files in the `scripts/` and `tests/` directories.** Maintaining code quality in open-source projects requires automated tooling to catch errors early and enforce consistent style. The iptv-org/iptv repository implements a robust linting setup that combines ESLint's flat config format with TypeScript-specific rules to validate its automation scripts and test suites. ## ESLint Configuration Architecture The linting setup centers on `eslint.config.mjs`, which defines how ESLint processes TypeScript files using the modern flat configuration format. ### Base Configuration and Parser The configuration uses `FlatCompat` to bridge legacy ESLint presets with the new flat config system. It extends `eslint:recommended` and `plugin:@typescript-eslint/recommended` to establish baseline rules for JavaScript and TypeScript code. The `@typescript-eslint/parser` handles TypeScript syntax parsing, configured with `ecmaVersion: 'latest'` and `sourceType: 'module'` to match the project's [`tsconfig.json`](https://github.com/iptv-org/iptv/blob/main/tsconfig.json) settings. The parser automatically reads TypeScript compiler options from [`tsconfig.json`](https://github.com/iptv-org/iptv/blob/main/tsconfig.json), ensuring ESLint understands the project's module resolution and type checking configuration. ### Plugins and Stylistic Rules The setup integrates two primary plugins: - **@typescript-eslint**: Provides TypeScript-specific linting rules - **@stylistic**: Enforces code formatting standards including indentation, line endings, and quote styles The configuration in `eslint.config.mjs` overrides default rules to match the project's coding standards: - **2-space indentation** enforced via `@stylistic/indent` - **Windows line endings** (`CRLF`) required through `@stylistic/linebreak-style` - **Single quotes** mandated for strings via `@stylistic/quotes` - **No semicolons** enforced through `@stylistic/semi` The configuration explicitly ignores test data files located in `tests/__data__/` to prevent linting errors in fixture files. ## Running ESLint on TypeScript Files The [`package.json`](https://github.com/iptv-org/iptv/blob/main/package.json) defines an npm script that executes ESLint across the project's TypeScript and JavaScript source files. ### Basic Linting Command Run the full linting suite across `scripts/` and `tests/` directories: ```bash npm run lint ``` This executes the equivalent command: ```bash npx eslint "scripts/**/*.{ts,js}" "tests/**/*.{ts,js}" ``` ESLint processes all `.ts` and `.js` files in these directories, reporting any violations of the configured rules. ### Auto-Fixing Linting Issues Many style violations can be automatically corrected. Run the fix command to resolve issues without manual intervention: ```bash npm run lint -- --fix ``` Or execute directly with npx: ```bash npx eslint "scripts/**/*.{ts,js}" "tests/**/*.{ts,js}" --fix ``` This command modifies files to comply with rules such as indentation, quote style, and semicolon usage. ## Key Configuration Files Understanding the relationship between these files helps when modifying linting behavior: - **`eslint.config.mjs`**: The primary ESLint configuration using the flat config format. Defines parsers, plugins, rules, and ignore patterns. - **[`package.json`](https://github.com/iptv-org/iptv/blob/main/package.json)**: Contains the `lint` npm script and declares dependencies including `eslint`, `@typescript-eslint/eslint-plugin`, `@typescript-eslint/parser`, and `@stylistic/eslint-plugin`. - **[`tsconfig.json`](https://github.com/iptv-org/iptv/blob/main/tsconfig.json)**: TypeScript compiler configuration that ESLint reads via `@typescript-eslint/parser` to understand module resolution and type checking settings. ## Summary - The iptv-org/iptv repository uses ESLint with TypeScript support via `@typescript-eslint/parser` and `@typescript-eslint/eslint-plugin`. - Configuration resides in `eslint.config.mjs` using the modern flat config format with `FlatCompat` for legacy preset support. - The `@stylistic` plugin enforces specific formatting rules including 2-space indentation, Windows line endings, single quotes, and no semicolons. - Run `npm run lint` to check all TypeScript files in `scripts/` and `tests/` directories, or add `--fix` to automatically correct style violations. ## Frequently Asked Questions ### How do I run ESLint on specific files instead of the entire codebase? Use npx with specific file paths rather than the npm script. For example, to lint only [`scripts/utils.ts`](https://github.com/iptv-org/iptv/blob/main/scripts/utils.ts), run `npx eslint scripts/utils.ts`. You can also target specific directories by adjusting the glob patterns, such as `npx eslint "scripts/core/**/*.ts"` to lint only the core subdirectory. ### Why does the configuration use Windows line endings instead of Unix? The `@stylistic/linebreak-style` rule in `eslint.config.mjs` explicitly enforces Windows-style CRLF line endings across the codebase. This standardizes the repository for contributors working on Windows systems and ensures consistent line ending behavior regardless of the operating system used by individual developers. ### Can I disable specific ESLint rules for test files? Yes, you can modify `eslint.config.mjs` to add override configurations for specific file patterns. While the current configuration only ignores `tests/__data__/`, you could add an object with `files: ["tests/**/*.ts"]` and a `rules` section that disables specific TypeScript rules for test files, or set `env: { jest: true }` if using Jest. ### What should I do if ESLint reports parser errors for experimental TypeScript syntax? Ensure your [`tsconfig.json`](https://github.com/iptv-org/iptv/blob/main/tsconfig.json) includes the necessary compiler options for the experimental features, as `@typescript-eslint/parser` reads this configuration. If the parser still fails, you may need to update the `@typescript-eslint` packages to versions that support the specific TypeScript syntax, or temporarily disable the specific rule causing the error in `eslint.config.mjs`.