--auto-watch broken in 3.1.3 (works in 3.1.1)

[jhildenbiddle]

Expected behaviour

• Karma will detect file change, automatically rerun tests with --auto-watch option, and changes will be reflected in the test output.

Actual behaviour

1. Saving changes to a test file triggers tests to rerun but changes are not reflected. Saving the test file a second time (without making changes) triggers tests to rerun again, this time with changes reflected.
2. Saving changes to a source file triggers tests to rerun but changes are not reflected. Only saving a test file will result in changes to a source file being reflected.

Environment Details

• Karma version (output of karma --version): 3.1.3
• Relevant part of your karma.config.js file: See css-vars-ponyfill/karma.conf

Steps to reproduce the behaviour

1. Clone css-vars-ponyfill release 1.16.0. This version is running Karma 3.1.3
2. On CLI: npm run dev. This runs both the build and test tasks in watch mode.
3. Edit one of the files in the /tests directory. Notice the file has to be saved twice in order for changes to be reflected.
4. Edit one of the files in the /src directory. Notice the changes are not reflected until a file in /tests is saved.
5. Downgrade to Karma 3.1.1: npm i -D karma@3.1.1
6. Perform steps 3 and 4 again. Notice that changes to test and source files are reflected immediately after saving (as expected).

[hunthunthunt]

I can confirm I'm seeing the same with the 3.1.3 release. If I pin the version to 3.1.1 in package.json then the bug goes away.

[cdbkr]

Same here. Downgrading to 3.1.1 works as expected (tests effectively re-run)

[devoto13]

This seems to be a duplicate of #3226, which is fixed by #3230. Just wait for a new release.

[jhildenbiddle]

Appears to be fixed in 3.1.4.

Thanks for the quick turnaround! 🎉