Bug/feature: ts-node should work with NODE_OPTIONS

[ORESoftware]

This works:

ts-node --inspect-brk foo.ts  # ❤️

but this doesn't

NODE_OPTIONS="--inspect-brk" ts-node foo.ts #  💥

I think it's because ts-node starts a child process, and because of that, we get an "address already in use" error. See the Node.js help issue attached.

Just try it for yourself and you will see the problem.

[ORESoftware]

See this issue for reference: nodejs/help#1007

[stelcheck]

I think the best option would be to wrap or convert https://github.com/TypeStrong/ts-node/blob/master/src/bin.ts into a bash/cmd script.

[ORESoftware]

@stelcheck I think the problem is that ts-node spawns a child process

https://github.com/TypeStrong/ts-node/blob/master/src/bin.ts#L53

so what we need is that spawned child process to debug on a different port than the parent process.

[stelcheck]

Why even spawn a port on the bin process? That process should not even react to NODE_OPTIONS; I can't think of a case where you'd want that as a user. This is why I was suggesting to either replace or wrap that file with a bash/sh/cmd file; these do not react to NODE_OPTIONS, and in the case of wrapping, options could then be forwarded the proper way to the spawned child process.

[ORESoftware]

dude I am so confused

this is ergonomic

NODE_OPTIONS="--inspect-brk" ts-node foo.ts

but it breaks... try it.

are you suggesting something more ergonomic, or less? Sounds like the latter to me. Perhaps demo the code you are talking about.

[stelcheck]

Apologies for the confusion.

I am suggesting a way to patch ts-node's code in a way that should solve your issue. Should we do that, running NODE_OPTIONS="--inspect-brk" should start working correctly as-is.

And please don't call me dude.

[stelcheck]

Actually, the simplest thing might just be to introduce a TS_NODE_OPTIONS environment variable which would be passed as NODE_OPTIONS to the spawned process. @blakeembrey would that be acceptable to you?

[stelcheck]

I preemptively created a PR implementing that behavior. @ORESoftware feel free to give it a spin and let me know if this would fix your current issue.

[ORESoftware]

@stelcheck yes I think that's a good idea - TS_NODE_OPTIONS seems like a good idea to me

[ORESoftware]

if you could make that a command line argument as well as an env variable, that'd be nice too, but probably not that important:

ts-node foo.ts --ts-node-options="--inspect-brk --harmony"

I really just need one or the other, but both would make me happy too

[blakeembrey]

For now, can you use ts-node -r ts-node/register? I'm hesitant to go too much further on the different node.js shell spawning tricks in use right now.

[ORESoftware]

@blakeembrey - in this case my node.js process is spawning children and I need to debug the children using Node.js exec flags, so it's not just about loading ts-node/register.

[stelcheck]

#499 Would allow you to use NODE_OPTIONS off the bat instead of using TS_NODE_OPTIONS

[ORESoftware]

cool I am all for anything that werks

[blakeembrey]

Closing with #536 as I won't be supporting the subprocess behaviour anymore.