eslint-plugin-local-i18n

An ESLint plugin that helps enforce internationalization (i18n) best practices by detecting hardcoded strings in your JavaScript, TypeScript, and JSX code.

Features

• 🌐 Detect Hardcoded Strings: Automatically identifies strings that should be internationalized
• ⚙️ Configurable: Flexible rules and exceptions to match your project needs
• 🎯 Attribute Checking: Validates text in JSX attributes like label, title, placeholder, and more
• 🚫 Smart Ignoring: Support for regex patterns and component-specific ignoring
• 📏 Minimum Length: Optional threshold to ignore very short strings

Installation

npm install --save-dev eslint-plugin-local-i18n

Or using your preferred package manager:

pnpm add -D eslint-plugin-local-i18n

yarn add --dev eslint-plugin-local-i18n

Configuration

Add the plugin to your ESLint configuration in eslint.config.js:

import localI18n from 'eslint-plugin-local-i18n';

export default defineConfig([
  {
    // React component files
    files: ['**/*.{js,jsx,ts,tsx}'],
    ignores: ['eslint.config.js', 'babel.config.js'],
    plugins: {'local-i18n': localI18n},
    rules: {
      'local-i18n/no-hardcoded-strings': [
        'error',
        {
          // optional config (defaults shown)
          attributes: [
            'label',
            'title',
            'placeholder',
            'alt',
            'aria-label',
            'accessibilityLabel',
            'accessibilityHint',
            'header',
            'headerTitle',
            'message',
          ],
          ignore: ['^https?://', '^[A-Z0-9_]+$'], // regex strings to allow
          ignoreComponents: ['Icon', 'Trans'], // skip these components' children
          minLength: 2, // ignore very short strings
        },
      ],
    },
  },
]);

Rules

no-hardcoded-strings

Detects hardcoded strings that should be internationalized.

Options

• attributes (array of strings): JSX attribute names to check for hardcoded strings
  • Default: ['label', 'title', 'placeholder', 'alt', 'aria-label']
• ignore (array of regex strings): Patterns to exclude from the rule
  • Example: ['^https?://', '^[A-Z0-9_]+$'] - ignores URLs and constant-like strings
• ignoreComponents (array of strings): Component names whose children should not be checked
  • Example: ['Icon', 'Trans'] - useful for components that typically don't need translation
• minLength (number): Minimum string length to trigger the rule
  • Default: 1
  • Useful to ignore very short strings like single characters

License

See LICENSE file for details.

Tests

Tests are written using RuleTester. To run the tests, use the following command:

pnpm test

Contributing

Contributions are welcome! For major changes, please open an issue first to discuss what you would like to change.

License

This project is licensed under the MIT License - see the LICENSE file for details.