@matthd/tsx v1.0.0
tsx
TypeScript Execute (tsx): The easiest way to run TypeScript in Node.js
Features
- Super fast!
- TypeScript REPL
- Supports
tsconfig.jsonpaths - Works in both CommonJS and ESM packages
!TIP Build your TypeScript projects?
Try pkgroll—the zero-config package bundler used by tsx!
pkgroll is a thin Rollup wrapper that makes it so simple for your package to support CommonJS, ESM, & TypeScript.
If you love tsx, you'll love pkgroll too!
About
tsx is a CLI command (alternative to node) for running TypeScript & ESM in both commonjs & module package types.
tsx is for you if you want:
- A command to just run TypeScript code without configuration
- Something so fast it's unnoticeable
Seamless integration across ESM and CJS dependencies
If you're getting the following error, give tsx a try! ``` Error [ERR_REQUIRE_ESM]: require() of ES Module <ESM package> from ./file.js not supported. Instead change the require of <ESM package> in ./file.js to a dynamic import() which is available in all CommonJS modules. ```
⚡️ Quick start
Try it out without setup! Just pass in a TypeScript file:
npx tsx ./script.tsInstallation
Local installation
To add tsx to an npm project as a development dependency:
npm install --save-dev tsxYou can reference it directly in the package.json#scripts object (you don't need npx here):
{
"scripts": {
"dev": "tsx ./file.ts"
}
}To use the binary, you can call it with npx while in the project directory:
npx tsx ...Global installation
If you want to use tsx anywhere on your computer without npx, install it globally:
npm install --global tsxThen, you can call tsx directly:
tsx ...Usage
tsx is a Node.js wrapper
tsx wraps around Node.js to enhance it with TypeScript support. Because it's a drop-in replacement for node, it supports all Node.js command-line flags.
# --no-warnings is a Node.js flag
tsx --no-warnings ./file.tsRun TypeScript / ESM / CJS module
Pass in a file to run:
tsx ./file.tsCustom tsconfig.json path
By default, tsconfig.json will be detected from the current working directory.
To set a custom path, use the --tsconfig flag:
tsx --tsconfig ./path/to/tsconfig.custom.json ./file.tsAlternatively, use the TSX_TSCONFIG_PATH environment variable:
TSX_TSCONFIG_PATH=./path/to/tsconfig.custom.json tsx ./file.tsWatch mode
Run file and automatically rerun on changes:
tsx watch ./file.tsAll imported files are watched except from the following directories:
node_modules, bower_components, vendor, dist, and .* (hidden directories).
Ignore files from watch
To exclude files from being watched, pass in a path or glob to the --ignore flag:
tsx watch --ignore ./ignore-me.js --ignore ./ignore-me-too.js ./file.tsTips
- Press Return to manually rerun
- Pass in
--clear-screen=falseto disable clearing the screen on rerun
REPL
Start a TypeScript REPL by running with no arguments:
tsxCache
Modules transformations are cached in the system cache directory (TMPDIR). Transforms are cached by content hash, so duplicate dependencies are not re-transformed.
Set the --no-cache flag to disable the cache:
tsx --no-cache ./file.tsAlternatively, use the TSX_DISABLE_CACHE environment variable:
TSX_DISABLE_CACHE=1 tsx ./file.tsNode.js Loader
tsx is a standalone binary designed to be used in place of node, but sometimes you'll want to use node directly. For example, when adding TypeScript & ESM support to npm-installed binaries.
To use tsx as a Node.js loader, pass it in to the --import flag. This will add TypeScript & ESM support for both Module and CommonJS contexts.
node --import tsx ./file.tsOr as an environment variable:
NODE_OPTIONS='--import tsx' node ./file.tsNote: The loader is limited to adding support for loading TypeScript/ESM files. CLI features such as watch mode or suppressing "experimental feature" warnings will not be available.
ESM only loader
If you only need to add TypeScript support in a Module context, you can use the ESM loader:
Node.js v20.6.0 and above
node --import tsx/esm ./file.tsNode.js v20.5.1 and below
node --loader tsx/esm ./file.tsCommonJS only loader
If you only need to add TypeScript & ESM support in a CommonJS context, you can use the CJS loader:
node --require tsx/cjs ./file.tsHashbang
If you prefer to write scripts that doesn't need to be passed into tsx, you can declare it in the hashbang.
Simply add #!/usr/bin/env tsx at the top of your file:
file.ts
#!/usr/bin/env tsx
console.log('argv:', process.argv.slice(2))And make the file executable:
chmod +x ./file.tsNow, you can run the file without passing it into tsx:
$ ./file.ts hello
argv: [ 'hello' ]VS Code debugging
Setup
Create the following configuration file in your project to setup debugging in VS Code:
.vscode/launch.json
{
"version": "0.2.0",
"configurations": [
/*
Each config in this array is an option in the debug drop-down
See below for configurations to add...
*/
],
}Debugging method 1: Run tsx directly from VSCode
Add the following configuration to the
configurationsarray in.vscode/launch.json:{ "name": "tsx", "type": "node", "request": "launch", // Debug current file in VSCode "program": "${file}", /* Path to tsx binary Assuming locally installed */ "runtimeExecutable": "${workspaceFolder}/node_modules/.bin/tsx", /* Open terminal when debugging starts (Optional) Useful to see console.logs */ "console": "integratedTerminal", "internalConsoleOptions": "neverOpen", // Files to exclude from debugger (e.g. call stack) "skipFiles": [ // Node.js internal core modules "<node_internals>/**", // Ignore all dependencies (optional) "${workspaceFolder}/node_modules/**", ], }In VSCode, open the file you want to run
Go to VSCode's debug panel, select "tsx" in the drop down, and hit the play button (F5).
Debugging method 2: Attach to a running Node.js process
This method works for any Node.js process and it's not specific to tsx
Add the following configuration to the
configurationsarray in.vscode/launch.json:{ "name": "Attach to process", "type": "node", "request": "attach", "port": 9229, "skipFiles": [ // Node.js internal core modules "<node_internals>/**", // Ignore all dependencies (optional) "${workspaceFolder}/node_modules/**", ], }Run tsx with
--inspect-brkin a terminal window:tsx --inspect-brk ./your-file.tsGo to VSCode's debug panel, select "Attach to process" in the drop down, and hit the play button (F5).
See the VSCode documentation on Launch Configuration for more information.
Contributing & Support
If you're interested in contributing, please check out the Contribution Guide. Your collaboration will be greatly appreciated!
If you're encountering a problem, take advantage of my Priority Support service for as little as $25. I'd be happy to help you out! 🙂
FAQ
Why is it named tsx?
tsx stands for "TypeScript execute". Mirroring npx, which stands for "Node.js package execute".
The 3-character package name offers an elegant developer experience, allowing usage like: npx tsx ....
Unfortunately, it overlaps with React's TSX/JSX, which stands for "TypeScript XML".
Does it type check the code it runs?
No. tsx is designed to be a simple TypeScript runner.
If you need type-checking, you can use an IDE like VS Code and it will type-check as you code via IntelliSense. Alternatively, you can run the TypeScript Compiler only for type-checking (e.g. tsc --noEmit) as a linting step.
How is tsx different from ts-node?
tsx and ts-node are both designed for executing TypeScript files in Node.js, but offer different approaches to suit user preferences.
Simple installation tsx is offered as a single binary without peer dependencies, and can be used without installation:
npx tsx ./script.ts. In comparison,ts-noderequires installing TypeScript or SWC as peer dependencies.Zero configuration tsx just works. It doesn't require initial setup or a
tsconfig.jsonfile, and doesn't get in the way of running your code.Sensible defaults tsx employs sensible defaults based on file imports and Node.js version, removing the need for certain
tsconfig.jsonsettings (that are designed for compilation rather than runtime). In comparison, ts-node relies on TypeScript's defaults (e.g.ES3target), which may be outdated.Module adaptability tsx automatically adapts between CommonJS and ESM modules, even supporting
require()of ESM modules, facilitating a smoother transition as the Node.js ecosystem evolves.Enhancements tsx gracefully handles new JS & TS syntax and features based on the Node.js version. It also supports
tsconfig.jsonpaths out of the box.Speed tsx utilizes esbuild to achieve rapid TypeScript compilation. In comparison, ts-node uses the TypeScript compiler by default. Because tsx doesn't type check, it's similar to
ts-node --esm --swc(which uses the SWC compiler).Watcher As a DX bonus, tsx also comes with watch mode to help you iterate faster!
For a detailed technical comparison, you can refer to this exhaustive comparison between tsx, ts-node, and other runtimes.
Does it have a configuration file?
No. tsx's integration with Node.js is designed to be simple & seamless. However, it supports a few properties from tsconfig.json to determine how to compile TypeScript files.
Does it have any limitations?
TypeScript & ESM transformations are handled by esbuild, so it shares the same limitations such as:
- Compatibility with code executed via
eval()is not preserved - Only certain
tsconfig.jsonproperties are supported emitDecoratorMetadatais not supported
For details, refer to esbuild's JavaScript caveats and TypeScript caveats documentation.
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