{"id":14559,"library":"eslint-html-parser","title":"ESLint HTML Parser","description":"eslint-html-parser is a custom ESLint parser designed to lint HTML files, including embedded JavaScript within `\n \n\n\n\n// src/app.js\nconsole.log(\"This standalone JS will also be linted.\");\n\n# Terminal commands to set up and run:\nnpm init -y\nnpm install --save-dev eslint eslint-html-parser\n# Create .eslintrc.json, src/index.html, src/app.js as shown above\nnpm run lint","lang":"javascript","description":"Demonstrates installation, basic ESLint configuration using eslint-html-parser for both HTML and standalone JavaScript files, and running the linter."},"warnings":[{"fix":"Migrate your ESLint configuration from `.eslintrc.*` to `eslint.config.js` (flat config) following ESLint's migration guide. Ensure `eslint-html-parser` is correctly specified in the new format, potentially using `languageOptions.parser` for file patterns.","message":"ESLint v9.0.0 and above deprecate the legacy `.eslintrc.*` configuration system in favor of flat config (`eslint.config.js`). `eslint-html-parser` examples typically use `.eslintrc.json`, which may require adaptation for newer ESLint versions.","severity":"breaking","affected_versions":">=9.0.0"},{"fix":"Upgrade Node.js to a supported version (e.g., LTS) and ESLint to version 6.x or newer via `npm install --save-dev eslint@latest`.","message":"The parser requires Node.js 6.x or later and ESLint 6.x or later. Using older versions will lead to installation or runtime errors.","severity":"gotcha","affected_versions":"<6.0.0 (ESLint) || <6.0.0 (Node.js)"},{"fix":"When running ESLint from the command line, use glob patterns like `eslint \"./**/*.{js,htm,html}\"` or explicitly list extensions: `eslint --ext .htm --ext .html --ext .js src/`.","message":"By default, ESLint only lints `.js` files when run on a directory. To lint HTML files, you must explicitly specify the extensions using glob patterns in the CLI or the `--ext` option.","severity":"gotcha","affected_versions":">=6.0.0"},{"fix":"Ensure that `parserOptions` in your `.eslintrc.*` or `eslint.config.js` accurately reflect the ECMAScript version and features used in your JavaScript code (e.g., `ecmaVersion: 2021`, `sourceType: 'module'`, `ecmaFeatures: { jsx: true }` for modern JS with JSX).","message":"The `parserOptions` for `eslint-html-parser` directly map to the options supported by the underlying JavaScript parser (defaulting to `espree`). Misconfiguring `ecmaVersion`, `sourceType`, or `ecmaFeatures` can lead to parsing errors for JavaScript content.","severity":"gotcha","affected_versions":">=6.0.0"}],"env_vars":null,"last_verified":"2026-04-19T00:00:00.000Z","next_check":"2026-07-18T00:00:00.000Z","problems":[{"fix":"Ensure `eslint-html-parser` is installed as a dev dependency: `npm install --save-dev eslint-html-parser`. Verify the `parser` setting in `.eslintrc.*` is exactly `\"eslint-html-parser\"`.","cause":"The `eslint-html-parser` package is not installed or the path to it is incorrect in the ESLint configuration.","error":"ESLint was configured to use the parser \"eslint-html-parser\" but that parser was not found."},{"fix":"Increase `parserOptions.ecmaVersion` in your ESLint config to a version that supports the syntax, e.g., `2021` or `latest`.","cause":"The `parserOptions.ecmaVersion` is set too low for modern JavaScript features like `await` or `async` functions.","error":"Parsing error: The keyword 'await' is reserved (ESLint)"},{"fix":"Ensure you have an `extends` configuration (e.g., `\"extends\": \"eslint:recommended\"`) or explicitly define the rules or plugins that provide the rules you intend to use.","cause":"While `eslint-html-parser` parses HTML and JS, it doesn't provide rules itself. This error means a configured rule is missing.","error":"Definition for rule 'no-console' was not found."},{"fix":"Add `.htm` and `.html` to your ESLint CLI command using `--ext .htm --ext .html` or ensure your `files` array in `eslint.config.js` or `overrides` in `.eslintrc.*` includes patterns like `\"**/*.{js,htm,html}\"`.","cause":"ESLint is not configured to process files with `.htm` or `.html` extensions, or the glob patterns/extensions in the CLI command are incorrect.","error":"No files were linted. Please ensure that 'files' is set correctly in your configuration."}],"ecosystem":"npm"}