Double-digit losses of coverage using coverlet.msbuild 3.0.0

[martincostello]

In multiple projects' dependabot updates to coverlet.msbuild from 2.9.0 to 3.0.0, there is a double-digit loss of apparent code coverage with zero other changes.

This seems to me like a bug of some kind, rather than a bug fix of aberrant data in a previous release, but if it genuinely is a reflection of true metric misreporting in v2 then fair enough.

Here are links to the generated pull requests and their respective drop in coverage for investigation:

PR	Coverage Change
justeattakeaway/JustSaying#846 (comment)	-21%
martincostello/alexa-london-travel#444 (comment)	-26%
martincostello/alexa-london-travel-site#856 (comment)	-13.44%
martincostello/api#539 (comment)	-22.73%
martincostello/azure-functions#221 (comment)	-13.38%
martincostello/website#686 (comment)	-17.93%

[Dave-EMIS]

Just tested V3 on my repo and seeing the line coverage drop from 4027 to 2100 (of 4085) using coverlet.collector.

Branch coverage remains the same.

This is a private repo, so I cannot share details.

I'm looking at the HTML in dotnet-reportgenerator-globaltool 4.8.1 using the OpenCover format (set via a runsettings file).

Some of the methods have "random" missing blocks - I cannot determine a pattern for the lines missed, but this is one generic example:

This is fully covered in 1.3.0

[martincostello]

Looks like line coverage has been affected where the "logical code line" spans over more than one line in the source file, such as a multiple-line constructor initializer:

var foo = new Bar()
{
    Baz = "qux"
};

[MarcoRossignoli]

Thanks for reporting this. We'll take a look asap.

[Dave-EMIS]

Looks like line coverage has been affected where the "logical code line" spans over more than one line in the source file, such as a multiple-line constructor initializer:

var foo = new Bar()
{
    Baz = "qux"
};

Yeah, that seems to be the case now you mention it, it is obvious :D

[MarcoRossignoli]

Weird, we had some guys using nightly and this issue wasn't reported and also strange for UTs.

[MarcoRossignoli]

cc: @daveMueller is you have some fast idea.

[JSkimming]

I've found the same issue in several of my projects, for example, JSkimming/Castle.Core.AsyncInterceptor#119

Here's the coverage report for reference:

https://2024-60778941-gh.circle-artifacts.com/0/Report/index.html