Workaround for not terminated npm process

[segrey]

Windows Terminal 1.22 release brings the fix for not terminated npm process (#15373). However, my application uses ConPTY as a library. ConPTY might be loaded from the OS, i.e. outdated without the fix.

What would you recommend to as a workaround here? Thanks in advance!

[segrey]

I'm thinking of writing 0x03 to the stdin pipe to let ConPTY raise CTRL_*_EVENTs before calling ClosePseudoConsole. What do you think? Maybe @lhecker?

[lhecker]

That has fundamentally the same issue. The dispatch of the signal stops on the first error and so it may never reach the npm child processes. (See the lengthy comment in the PR diff.)

I believe you have to wait for the PR to ship as a inbox fix.

[segrey]

@lhecker Thanks for the answer. Yep, I've already bundled ConPTY v1.22 (thank you for the fix too!). However, there are cases when ConPTY will be loaded from system, and in this case, the issue is still actual, unfortunately.

Interestingly, sending 0x03 to the stdin pipe does help me (with ConPTY not having the fix). Can it be that 0x03 leads to GenerateConsoleCtrlEvent and if the child npm process is attached to the conosle, it receives the events?

[lhecker]

I suspect this only fixes your specific edge case but will then fail to work for more complex cases. If you read the PR, you'll see how fundamentally, the "early abort" that the previous code did, breaks any and all assumptions about this. It's just plain wrong.

While I would not endorse your workaround (because it's technically not "correct"), if I was you, and it fixed this issue for me, I'd go with it.

[segrey]

Thanks, I took a closer look at a5dc395.

Interesting, what did EndTask(EventType=CTRL_C_EVENT) return previously? Seems if it would be not STATUS_SUCCESS, then pressing Ctrl+C shouldn't be working when npm run dev command is running, right?

The npm run dev command usually spawns the following process tree:

* the parent npm process
** shell process
*** child npm process (actual user's application)

All processes are attached to the console. The parent npm process is configured to survive on CTRL_C_EVENT (https://github.com/npm/cli/blob/v11.4.2/node_modules/%40npmcli/run-script/lib/signal-manager.js#L5) and forward it to the spawned process.

I'm in the dark about possible outcome of EndTask(EventType=CTRL_C_EVENT) for processes refusing to exit. Could you please help?