Coverlet: Incorrect coverage reporting 🐛

[atifaziz]

The coverage report for 87135a5d0c3c5a27db83509fba01774dd20201d9 claims that DictionaryExtensions.cs has 75% coverage. It only has one method:

https://github.com/tonerdo/coverlet/blob/87135a5d0c3c5a27db83509fba01774dd20201d9/src/coverlet.core/Extensions/DictionaryExtensions.cs#L7-L14

According to the report, lines 9, 10 and 13 are covered but not line 12 (thus the 75%). How can 13 be covered but not 12? Is this a bug or am I misreading something? The only test for this method…

https://github.com/tonerdo/coverlet/blob/87135a5d0c3c5a27db83509fba01774dd20201d9/test/coverlet.core.tests/Extensions/DictionaryExtensionsTests.cs#L10-L17

…seems to cover it 100%.

[tonerdo]

@atifaziz I have noticed this little kinks here and there. Currently trying to find the root cause, intend to have it fixed by this weekend

[OneCyrus]

we saw similar issues here. some lines between covered ones where missing where it wasn't possible to branch.

[tonerdo]

@OneCyrus @atifaziz This issue has been fixed in #10 and you'll see that the coverage for this repo increased as a result.

It was actually a pretty straightforward fix and a good side effect is it sets the foundation for branch coverage support. This fix will be in a new NuGet package I'll release this weekend, in the future I'll setup a nightly CI package publish so improvements can get out faster.

Cheers

[atifaziz]

@tonerdo Thanks and looking forward to trying out the new package soon after it's up.

[tonerdo]

@atifaziz New NuGet package release: https://www.nuget.org/packages/coverlet.msbuild/1.0.1

[tonerdo]

@OneCyrus lemme know if the new NuGet package also fixes the issues you were seeing regarding coverage accuracy

[OneCyrus]

it improved here but there are still some missing parts. e.g.:

[tonerdo]

Thanks for pointing that out. Any other examples you can show? A larger sample size is always helpful

[OneCyrus]

here's another example:

it looks like it doesn't like LINQ. all the missing things I saw are related to LINQ.

[tonerdo]

I'm not surprised, the IL the compiler generates for LINQ is horrendous. I'll take a closer look, thanks

[tonerdo]

@OneCyrus kindly use the latest NuGet bits which has branch coverage support and see if this helps fix this issue. Thanks