Support TypeScript extensions when using --test flag.

[remcohaszing]

Feature request

Running node --test discovers test files. However, it doesn’t discover files that end with the .ts, .cts, .mts, or .tsx extensions. It would be nice if tsx supports this.

Why?

I would like to leverage the builtin Node test runner. I also like using tsx. They work great together, except for this quirk meaning I need to specify all tests as command line parameters.

Alternatives

The workaround is to specify test files as command line parameters. This works, but it’s not ideal.

Additional context

https://nodejs.org/api/test.html#test-runner-execution-model

[privatenumber]

Happy to accept a PR to add support.

IIRC there isn't an API to extend this. I recommend starting by opening a feature request with Node.js.

[privatenumber]

This issue is for implementing a feature, and these workarounds aren't productive towards that goal so I'm going to hide them.

For anyone encountering this problem:

We're looking for a working approach that actually extends Node.js' --test glob.

Personally, I don't use Node's --test feature so I'm not incentivized to prioritize this. But I'm happy to prioritize and support anyone that wants to take initiative on this.

[privatenumber]

Investigated this.

Seems like the node --test flag accepts globs from v21, so you can simply pass in one that catches TypeScript files.

Since everything passed into tsx is passed down to Node, you can also pass it into tsx:

tsx --test '**/*.test.ts'

(Note: quoting the glob prevents your shell from expanding it so Node will expand it instead)

The default glob Node uses is here:
https://github.com/nodejs/node/blob/v21.2.0/lib/internal/test_runner/utils.js#L51

So we can alter that to support TS extensions for the default behavior with TS support:

tsx --test '**/{test,test/**/*,test-*,*[.-_]test}.?(c|m)@(t|j)s'

I plan on intercepting the --test flag to use this default instead.

[remcohaszing]

Dropped support for Node.js 16 also means node:test#run() can be used.

[karlhorky]

Thanks for this issue and #410!

@remcohaszing am I understanding that you are now (as of tsx@4.4.0) able to run all Node.js tests like this?

tsx --test