For more awesome packages, check out my homepage💛

Note: options in 2.0.0 is not completely compatible with 1.x.x !! see the details

Features

• 🚀 Auto merge: Automatically finds and merges all .d.ts files from specified directories
• 🔄 Content replacement: Built-in string/regex replacement functionality with support for functions
• 🎯 Flexible filtering: Include/exclude patterns using glob syntax
• 📦 Zero dependencies: Lightweight and fast
• 🔧 Simple configuration: Minimal setup required

Usage

Basic Usage

// rollup.config.js
import dts from 'rollup-plugin-dts';
import dtsMerger from 'rollup-plugin-dts-merger';

export default {
  input: 'src/index.ts',
  output: { file: 'dist/index.d.ts', format: 'es' },
  plugins: [
    dts(), // Generate .d.ts first
    dtsMerger({
      include: ['src/**'], // ← this is default value
      exclude: ['test/**', 'tests/**', 'dist/**', 'node_modules/**'], // ← this is default value
      mergeInto: 'dist/index.d.ts', // ← this is default value
      replace: {
        '/*__DEV__*/': 'export',
        __VERSION__: '2.0.0',
      },
    }), // Then merge additional .d.ts files
  ],
};

Options

include

• Type: Glob filter pattern
• Default: ['src/**']
• Description: Glob patterns to include files/directories. All .d.ts files in these locations will be merged.

exclude

• Type: Glob filter pattern
• Default: ['test/**', 'tests/**', 'dist/**', 'node_modules/**']
  • Definitely exclude node_modules(even if you pass [] to it) to avoid unnecessary processing
• Description: Glob patterns to exclude files/directories from merging.

mergeInto

• Type: string
• Default: 'dist/index.d.ts'
• Description: Target file path where all .d.ts content will be merged into. This file must exist before merging (usually created by rollup-plugin-dts).

replace

• Type: Record<string, any>
• Default: {}
• Description: Key-value pairs for content replacement. Values can be:
  • string: Direct replacement
  • function: (key: string) => string - Dynamic replacement based on the key
  • other types: Converted to string

Replace Examples

{
  replace: {
    // String replacement
    '__VERSION__': '2.0.0',

    // Remove development flags
    '/*__DEV__*/': '',

    // Add export keywords
    '/*__EXPORT__*/': 'export',

    // Function-based replacement
    '__TIMESTAMP__': () => Date.now().toString(),

    // Type/value replacements
    'DEBUG_MODE': false,
    'MAX_ITEMS': 100,
    'API_ENDPOINT': null
  }
}

How It Works

1. Find files: Scans directories matching include patterns for .d.ts files
2. Filter: Excludes files matching exclude patterns
3. Replace content: Applies replace rules to both target file and source files
4. Merge: Appends all source file content to the target file with source path comments

License

MIT

Author

• Name: KasukabeTsumugi
• Email: [email protected]

✨ Enjoy merging your TypeScript declarations! ✨