evanw

This is a helper command to run TypeScript applications easily using esbuild.

esbuild is super fast and makes it possible to build and run TypeScript files on the fly. Even though I use this mainly for TypeScript, there are more languages supported by esbuild, you can find the list in their website (link above).

This is mostly useful for running one time scripts and testing things locally, and it is not recommended to use this module in production.

Usage without installation

Using npx you don't need to install anything, run your application right away:

npx evanw /path/to/file.ts

If you don't want to use npx follow the global installation section.

Usage inside npm scripts

You can install evanw as a development dependency and use it in your npm scripts.

npm install --save-dev evanw

  "scripts": {
    "test": "evanw ./tests"
  },

Global installation

evanw does not come with esbuild itself, so you would have to install that separately using your favorite package manager.

# you can do this with npm
npm install -g esbuild

Then you can go ahead and install evanw

npm install -g evanw

Running

Now you can run TypeScript applications the same way you would run them with node, all the node options are also available.

evanw /path/to/file.ts

Changing esbuild options

By default the options used for building the app are --bundle and --platform=node, you can replace those options by setting the ESBUILD_OPTIONS environment variable.

export ESBUILD_OPTIONS='--bundle --platform=node --outfile=x.js'
evanw /path/to/file.ts

Reasoning

I created this script mostly because it's a common use-case for me to build and run TypeScript applications, there are other solutions that work perfectly fine (e.g. ts-node), however the performance gain by esbuild tempted me to have this command with esbuild.

Name

Initially I called this script es-node, but because a package existed with a similar name, NPM didn't allow me to publish that, so I decided to name this after the creator of esbuild, Evan W., I hope he doesn't mind :)

Contributions

If you faced any problem that you couldn't find a solution for, and/or you want to improve this script, feel free to create an issue on GitHub. Contributions are welcome :)