swc-node

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Fast TypeScript/JavaScript transformer without node-gyp and postinstall script.

Usage

Run TypeScript with node, without compilation or typechecking:

npm i -D @swc-node/register
node -r @swc-node/register script.ts
node --import @swc-node/register/esm-register script.ts # for esm project with node>=20.6
node --loader @swc-node/register/esm script.ts # for esm project with node<=20.5, deprecated

Pass --enable-source-maps to node for esm projects

Set environment variable SWCRC=true when you would like to load .swcrc file

SWCRC=true node -r @swc-node/register script.ts

#!/usr/bin/env node --import swc-register-esm

// your code

run with shebang, add TS_NODE_PROJECT=null(#!/usr/bin/env TS_NODE_PROJECT=null node --import swc-register-esm) to use ignore tsconfig.json

@swc-node/core

Fastest TypeScript transformer.

Detail: @swc-node/core

Benchmark

transform RxJS AjaxObservable.ts to ES2015 & CommonJS JavaScript. Benchmark code: bench

Hardware info:

Model Name: MacBook Pro
Model Identifier: MacBookPro15,1
Processor Name: 6-Core Intel Core i7
Processor Speed: 2.6 GHz
Number of Processors: 1
Total Number of Cores: 6
L2 Cache (per Core): 256 KB
L3 Cache: 12 MB
Hyper-Threading Technology: Enabled
Memory: 16 GB

transformSync

esbuild x 510 ops/sec ±1.28% (88 runs sampled)
@swc-node/core x 438 ops/sec ±1.00% (88 runs sampled)
typescript x 28.83 ops/sec ±10.20% (52 runs sampled)
babel x 24.21 ops/sec ±10.66% (46 runs sampled)
Transform rxjs/AjaxObservable.ts benchmark bench suite: Fastest is esbuild

transform parallel

UV_THREADPOOL_SIZE=11 yarn bench

@swc-node/core x 1,253 ops/sec ±0.90% (75 runs sampled)
esbuild x 914 ops/sec ±1.31% (77 runs sampled)
Transform rxjs/AjaxObservable.ts parallel benchmark bench suite: Fastest is @swc-node/core

yarn bench

@swc-node/core x 1,123 ops/sec ±0.95% (77 runs sampled)
esbuild x 847 ops/sec ±3.74% (71 runs sampled)
Transform rxjs/AjaxObservable.ts parallel benchmark bench suite: Fastest is @swc-node/core

@swc-node/jest

Fastest jest TypeScript transformer.

Detail: @swc-node/jest

Performance glance

Testing in pure TypeScript project, compile target is ES2018. Running with npx jest --no-cache, ts-jest was configured with isolatedModules: true

ts-jest

Test Suites: 49 passed, 49 total
Tests:       254 passed, 254 total
Snapshots:   53 passed, 53 total
Time:        54.631 s
Ran all test suites.
✨  Done in 62.71s.

@swc-node/jest

Test Suites: 49 passed, 49 total
Tests:       254 passed, 254 total
Snapshots:   53 passed, 53 total
Time:        10.511 s
Ran all test suites.
✨  Done in 14.34s.

@swc-node/register

Faster ts-node/register/transpile-only alternative.

Detail: @swc-node/register

Development

Install dependencies

• pnpm i

Build and Test

• pnpm build

• pnpm test

Sponsors