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eslint-plugin-capo

v0.1.0

Published

ESLint plugin to validate HTML <head> elements based on capo.js rules

Vulnerabilities

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Links

Git

Maintainers

rviscomirviscomi

Keywords

eslinteslint-pluginhtmlheadvalidationcapoperformanceseo

Readme

eslint-plugin-capo

ESLint plugin to validate HTML <head> elements based on capo.js validation rules. This plugin helps catch common issues with metadata, performance problems, accessibility concerns, and deprecated practices in HTML head sections.

Installation

npm install --save-dev eslint-plugin-capo @html-eslint/parser

Requirements:

  • ESLint >= 8.21.0
  • Node.js >= 18.18.0
  • @html-eslint/parser >= 0.47.0

Usage

Flat Config (ESLint 9+)

Create or update your eslint.config.js:

import capo from 'eslint-plugin-capo';
import htmlParser from '@html-eslint/parser';

export default [
  {
    files: ['**/*.html'],
    languageOptions: {
      parser: htmlParser,
    },
  },
  capo.configs.recommended,
];

Configuration Presets

See the rules documentation for more information.

recommended (Default)

Balanced rules for production use:

import capo from 'eslint-plugin-capo';

export default [capo.configs.recommended];

Other presets

Besides than the recommended preset, there are other presets available:

  • strict - All rules as errors
  • performance - Performance-focused rules only
  • accessibility - Accessibility-focused rules only
  • ordering - Element ordering validation only

Custom Configuration

import capo from 'eslint-plugin-capo';

export default [
  {
    plugins: {
      capo,
    },
    rules: {
      'capo/no-invalid-head-elements': 'error',
      'capo/require-title': 'error',
      'capo/no-duplicate-base': 'error',
      'capo/no-meta-csp': 'warn',
      'capo/no-invalid-http-equiv': 'warn',
      'capo/valid-meta-viewport': 'error',
      'capo/valid-charset': 'error',
      'capo/no-default-style': 'warn',
      'capo/no-unnecessary-preload': 'warn',
      'capo/require-order': 'warn', // Optional: validate element ordering
    },
  },
];

Background

This plugin implements the validation rules from capo.js, a tool for determining the optimal order of elements in the HTML <head>.

Contributing

Contributions are welcome! Please open an issue or PR on GitHub.

License

Apache-2.0

Credits

Based on validation rules from capo.js by Rick Viscomi. Inspired by Harry Roberts' work on ct.css and Vitaly Friedman's Nordic.js 2022 presentation.