Tool	Execution Time	Comparison
lightning-dts	0.64ms ⚡️	baseline
rolldown-plugin-dts	49.51ms	77.74x slower
rollup-plugin-dts	84.43ms	132.55x slower
dts-bundle-generator	833.71ms	1308.90x slower

Benchmarks run on identical code with sourcemap generation enabled

Features

Ultra-Fast: Generate TypeScript declaration files at lightning speed
Bundling: Not just generation, bundles all declarations into a single .d.ts file ready to ship
Sourcemaps: Full sourcemap support for better debugging with the same speed
Node Module Resolution: Seamlessly resolves types from node_modules
Configurable: Customize with TSConfig options

Installation

# npm
npm install lightning-dts --save-dev

# bun
bun add lightning-dts --dev

# pnpm
pnpm add lightning-dts -D

Usage

import { generateDts } from 'lightning-dts';

// Basic usage
const result = generateDts('./src/index.ts');

// With options
const result = generateDts('./src/index.ts', {
	rootDir: './src',
	sourcemap: true,
	stripInternal: true,
	preferredTsConfigPath: './tsconfig.build.json',
	resolve: true, // resolve all external modules from node_modules
});

// Access the generated declaration
console.log(result.code);

// Access sourcemap if enabled
console.log(result.map);

// Handle any errors
if (result.errors.length > 0) {
	console.error(result.errors);
}

API

`generateDts(entryFilePath, options?)`

Generates and bundles TypeScript declaration files.

Parameters

entryFilePath: Path to the entry TypeScript file
options: (Optional) Configuration options
- rootDir: Root directory of the project (default: process.cwd())
- preferredTsConfigPath: Path to the preferred tsconfig.json file (by default, the closest tsconfig.json will be used)
- resolve: Controls which external modules should be resolved:
  - true to resolve all external modules
  - Array of strings or RegExp to match specific modules
  - false or undefined to disable external resolution
- sourcemap: Generate sourcemap (default: false)
- stripInternal: Remove declarations marked as @internal (default: false)

Returns

{
  code: string;     // The generated .d.ts content
  errors: OxcError[];  // Any errors encountered during generation
  map?: SourceMap;  // Sourcemap (if enabled)
}