Perform async work synchronously in Node.js using `worker_threads` with first-class TypeScript support.
npm install synckit
Perform async work synchronously in Node.js/Bun using worker_threads with first-class TypeScript and Yarn P'n'P support.
- Usage
- Install
- API
- Types
- Options
- Envs
- TypeScript
- node (Default, Node 22.6+)
- bun (Default, Bun)
- ts-node (Default)
- esbuild-register
- esbuild-runner
- oxc
- swc
- tsx
- Benchmark
- Sponsors
- Backers
- Who are using synckit
- Acknowledgements
- Changelog
- License
``shyarn
yarn add synckit
$3
js
// runner.js
import { createSyncFn } from 'synckit'// the worker path must be absolute
const syncFn = createSyncFn(require.resolve('./worker'), {
tsRunner: 'tsx', // optional, can be
'node' | 'ts-node' | 'esbuild-register' | 'esbuild-runner' | 'tsx'
})// do whatever you want, you will get the result synchronously!
const result = syncFn(...args)
js
// worker.js
import { runAsWorker } from 'synckit'runAsWorker(async (...args) => {
// do expensive work
return result
})
`You must make sure, the
is serializable by Structured Clone Algorithm$3
ts
export interface GlobalShim {
moduleName: string
/* undefined means side effect only /
globalName?: string
/**
* 1. undefined or empty string means default, for example:
*
* `js
* import globalName from 'module-name'
* `
*
* 2. means namespaced, for example:
*
* `js
import as globalName from 'module-name'
* `
*/
named?: string | null
/**
* If not , the shim will only be applied when the original
* globalName unavailable, for example you may only want polyfill
* globalThis.fetch when it's unavailable natively:
*
* `js
* import fetch from 'node-fetch'
*
* if (!globalThis.fetch) {
* globalThis.fetch = fetch
* }
* `
*/
conditional?: boolean
}
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1.
same as env SYNCKIT_EXEC_ARGV
2. : Similar like env SYNCKIT_GLOBAL_SHIMS but much more flexible which can be a GlobalShim Array, see GlobalShim's definition for more details
3. timeout same as env SYNCKIT_TIMEOUT
4. : Please refer Node.js worker_threads documentation
5. tsRunner same as env SYNCKIT_TS_RUNNER$3
1.
: List of node CLI options passed to the worker, split with comma ,. (default as []), see also node docs
2. SYNCKIT_GLOBAL_SHIMS: Whether to enable the default DEFAULT_GLOBAL_SHIMS_PRESET as globalShims
3. : timeout for performing the async job (no default)
4. SYNCKIT_TS_RUNNER: Which TypeScript runner to be used, it could be very useful for development, could be 'node' | 'ts-node' | 'esbuild-register' | 'esbuild-runner' | 'oxc' | 'swc' | 'tsx', node or ts-node will be used by default accordingly, make sure you have installed them already$3
####
node (Default, Node 22.6+)On recent
Node versions, you may select this runner to execute your worker file (a .ts file) in the native runtime.As of
Node v23.6, this feature is supported out of the box. For Node >=22.6 <23.6, this feature is supported via --experimental-strip-types flag. Visit the documentation to learn more.When
synckit detects the process to be running with supported Node versions (>=22.6), it will execute the worker file with the node runner by default, you can disable this behavior by setting --no-experimental-strip-types flag via NODE_OPTIONS env or cli arg.####
bun (Default, Bun)Bun supports TypeScript natively.When
synckit detects the process to be running with Bun, it will execute the worker file with the bun runner by default.In this case,
synckit doesn't do anything to the worker itself, it just passes through the worker directly.####
ts-node (Default)Prior to Node v22.6, you may want to use
ts-node to execute your worker file (a .ts file).If you want to use a custom tsconfig as project instead of default
tsconfig.json, use TS_NODE_PROJECT env. Please view ts-node for more details.If you want to integrate with tsconfig-paths, please view ts-node for more details.
####
esbuild-registerPlease view [
][] for its document####
esbuild-runnerPlease view [
][] for its document####
oxcPlease view [
][] for its document####
swcPlease view [
][] for its document####
tsxPlease view [
][] for its documentBenchmark
The following are the benchmark results of
synckit against other libraries with Node.js v20.19.0 on my personal MacBook Pro with 64G M1 Max:`sh
cjs
┌───────────┬────────────┬──────────────┬───────────────────┬─────────────┬────────────────┬───────────────────┬────────────────────────┬───────────┬─────────────────┐
│ (index) │ synckit │ sync-threads │ perf sync-threads │ deasync │ perf deasync │ make-synchronized │ perf make-synchronized │ native │ perf native │
├───────────┼────────────┼──────────────┼───────────────────┼─────────────┼────────────────┼───────────────────┼────────────────────────┼───────────┼─────────────────┤
│ loadTime │ '17.26ms' │ '1.49ms' │ '11.57x slower' │ '146.55ms' │ '8.49x faster' │ '1025.77ms' │ '59.42x faster' │ '0.29ms' │ '59.71x slower' │
│ runTime │ '143.12ms' │ '3689.15ms' │ '25.78x faster' │ '1221.11ms' │ '8.53x faster' │ '2842.50ms' │ '19.86x faster' │ '12.64ms' │ '11.33x slower' │
│ totalTime │ '160.38ms' │ '3690.64ms' │ '23.01x faster' │ '1367.66ms' │ '8.53x faster' │ '3868.27ms' │ '24.12x faster' │ '12.93ms' │ '12.41x slower' │
└───────────┴────────────┴──────────────┴───────────────────┴─────────────┴────────────────┴───────────────────┴────────────────────────┴───────────┴─────────────────┘
`sh
esm
┌───────────┬────────────┬──────────────┬───────────────────┬─────────────┬────────────────┬───────────────────┬────────────────────────┬───────────┬─────────────────┐
│ (index) │ synckit │ sync-threads │ perf sync-threads │ deasync │ perf deasync │ make-synchronized │ perf make-synchronized │ native │ perf native │
├───────────┼────────────┼──────────────┼───────────────────┼─────────────┼────────────────┼───────────────────┼────────────────────────┼───────────┼─────────────────┤
│ loadTime │ '23.88ms' │ '2.03ms' │ '11.75x slower' │ '70.95ms' │ '2.97x faster' │ '400.24ms' │ '16.76x faster' │ '0.44ms' │ '54.70x slower' │
│ runTime │ '139.56ms' │ '3570.12ms' │ '25.58x faster' │ '1150.99ms' │ '8.25x faster' │ '3484.04ms' │ '24.96x faster' │ '12.98ms' │ '10.75x slower' │
│ totalTime │ '163.44ms' │ '3572.15ms' │ '21.86x faster' │ '1221.93ms' │ '7.48x faster' │ '3884.28ms' │ '23.77x faster' │ '13.42ms' │ '12.18x slower' │
└───────────┴────────────┴──────────────┴───────────────────┴─────────────┴────────────────┴───────────────────┴────────────────────────┴───────────┴─────────────────┘
`See benchmark.cjs and benchmark.esm for more details.
You can try it with running
by yourself. Here is the benchmark source code.Sponsors and Backers
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| 1stG | RxTS | UnTS |
| ---------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------- |
|  |  |  |
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| 1stG | RxTS | UnTS |
| ------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------- |
|  |  |  |
Who are using
synckit
-
-
-
-
-
- Acknowledgements
and sync-threads.Changelog
Detailed changes for each release are documented in CHANGELOG.md.
License
[MIT][] © [JounQin][]@[1stG.me][]
[
esbuild-register]: https://github.com/egoist/esbuild-register
[esbuild-runner]: https://github.com/folke/esbuild-runner
[@oxc-node/core]: https://github.com/oxc-project/oxc-node
[@swc-node/register]: https://github.com/swc-project/swc-node/tree/master/packages/register
[tsx`]: https://github.com/esbuild-kit/tsx