Jest hangs at "testing changes"

[morungos]

Environment

1. node -v: v6.12.0

2. npm -v: 3.10.10

3. node node_modules/.bin/jest --version: v21.2.1

4. npm ls react-scripts (if you haven’t ejected): NA, no React etc.

5. Operating system: macOS 10.13.2

Steps to Reproduce

None. It happens out of the box. Strangely, I have another system, with virtually identical setup (save Node v6.12.2) which doesn't have a problem with Jest hanging. I'll bring the versions into exact line and confirm status if different. So there is definitely an environment/setup/config issue causing different behaviour.

Expected Behavior

Jest completes.

Actual Behavior

Jest does it's initial scan, then mentions "watch mode", then spins at "testing changes". Essentially it's indistinguishable from #128, but without the errors. Jest completes its tests both the initial and the later ones successfully, but VSCode is wedged on "testing changes".

There's also a process listed:

  PID TTY           TIME CMD
65124 ??         0:02.67 node node_modules/.bin/jest --json --useStderr --outputFile /var/folders/p7/sfg0k3392314nk2m5vnbm2nc0000gn/T/jest_runner.json --watch

When run manually, this ends correctly at the "Watch Usage" menu.

The behaviour appears cosmetic. Future changes and edits are detected, and re-run the tests. It's just the front end hides that by showing, in one environment, the spinning "testing changes" in the status bar.

No funny DB code or anything else: this isn't React, or a complex app, it's a straight JS library.

[morungos]

Hmmm, it seems to have stabilized and fixed itself. Which is weird. There must have been some state which wasn't cleared right. It was also marking, for a while, there being errors in Jest when there weren't, and even when all tests passed.

[seanpoulter]

Thanks for taking the time to report the issue @morungos. That sounds like some strange behavior!

I'm closing the issue since we can't reproduce the problem but please re-open as necessary. I've found the easiest way to troubleshoot issues is debugging the extension and opening a minimal repo that reproduces the problem. Since this may be more machine or configuration specific, you might need to take a look on your end starting with the steps in this comment. I'm happy to help investigate if we get to that point.