Different coverage reported on Windows vs Linux

[oliversalzburg]

• Version: 5.0.2
• Platform: Linux runner-4xz_xPE1-project-77-concurrent-0 4.4.0-1052-aws Incorrect coverage reported for ternaries in some situations #61-Ubuntu SMP Mon Feb 12 23:05:58 UTC 2018 x86_64 GNU/Linux

I get differing coverage reports depending on if I run the test on Windows 10 x64 vs Ubuntu x64. Both platforms are running Node 12.9.1. The issue seems to only affect specific files in the test suite/application.

Windows

Ubuntu

The pattern is always the same in all affected files. The imports are shown as not covered and so is the class and method declaration.

When I tried to isolate the behavior in a smaller projects, I was not able to. Any suggestions on how to approach this so I can get more useful information?

[bcoe]

@oliversalzburg could you provide a repository with a minimal reproduction of the issue you're seeing?

[oliversalzburg]

I actually tried working on one for a while, but when I removed all our private dependencies, I was no longer to reproduce the issue :(

I was hoping someone might have an idea of why this is happening so I could investigate into a certain area. I will try my luck again with a repro and report back.

[bcoe]

👍 are you using anything that transpiles code, like Babel, TypeScript, or ESM?

[oliversalzburg]

I'm not. This is plain JS running in Node.

[oliversalzburg]

Ugh, can't reproduce it at work at all right now. Either the code has changed so that the issue no longer appears or it's something special about my home workstation. I'll check it out tonight.

I can currently no longer reproduce this. Linux and Windows are reporting the same coverage. As my workstations all run Windows, my original plan to reproduce this on another workstation is pointless as the wrong coverage report came originally from Linux.

Not sure we'll be able to track this down to a specific change again. I'll reopen if we can, otherwise I'll just be happy that the report is correct now.