ts-node — Use SWC to Speed up TypeScript Code

ts-node is a TypeScript execution engine for Node.js. It allows you to run your TypeScript code directly without precompiling your TypeScript code to JavaScript. ts-node transforms TypeScript to JavaScript in-memory without writing it to disk.

Large projects may still take some time to process. This is where SWC comes handy. SWC is a TypeScript-compatible transpiler written in Rust. This makes the processing of TypeScript code faster than the vanilla TypeScript compiler.

This tutorial shows you how to run your TypeScript code using ts-node with SWC.

TypeScript Series Overview

Running TypeScript with ts-node and SWC

You can run your TypeScript code with ts-node and tell it to use SWC for compilation.

Installing SWC Dependencies

In modern code bases you must install @swc/core as a project dependency. You can install it using NPM:

npm i -D @swc/core  

In case your TypeScript target is below es2015 and you’re using async/await or generator function you must also install the regenerator-runtime package:

npm i -D @swc/core regenerator-runtime  

Use ts-node with SWC

You can use the --swc flag in case ts-node is globally available on your machine. Append that flag and run the TypeScript file:

ts-node --swc server.ts  

You may also configure ts-node to use SWC in your tsconfig.json file. Specify a ts-node object at the root of your tsconfig.json and tell it to use SWC:

  "ts-node": {
    "swc": true

Use @swc/helpers Instead of TypeScript’s „importHelpers“

TypeScript provides importHelpers for downleveling operations. You can also replace the import helpers with SWC helpers. You must install the @swc/helpers package if importHelpers are enabled in your project:

npm i -D @swc/helpers  

SWC uses @swc/helpers instead of tslib bringing some more speed improvements.

Enjoy running your TypeScript code with speed!

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