Added logging to Coverage to help with debugging

[derhally]

There was no indication why coverage didn't occur because the exception occurring inside Coverage class was being swallowed.

I was missing an dependency and had no way of knowing that. This should help.

[codecov]

Codecov Report

Merging #341 into master will decrease coverage by 0.09%.
The diff coverage is 75%.

@@            Coverage Diff            @@
##           master     #341     +/-   ##
=========================================
- Coverage    87.1%   87.01%   -0.1%     
=========================================
  Files          31       32      +1     
  Lines        3033     3050     +17     
=========================================
+ Hits         2642     2654     +12     
- Misses        391      396      +5

[codecov]

Codecov Report

Merging #341 into master will decrease coverage by 0.1%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #341      +/-   ##
==========================================
- Coverage    87.1%   86.99%   -0.11%     
==========================================
  Files          31       31              
  Lines        3033     3092      +59     
==========================================
+ Hits         2642     2690      +48     
- Misses        391      402      +11

[tonerdo]

@derhally thanks a lot for this! Will take a look later today

[MarcoRossignoli]

Added some thoughts

Thank's a lot for help!

[MarcoRossignoli]

@derhally CI fail on MSBuildLogger.cs for wrong namespace Coverlet.Core.ILogger

[MarcoRossignoli]

@tonerdo @derhally I did some tests I cannot show LogInformation/LogVerbose(https://docs.microsoft.com/en-us/visualstudio/msbuild/obtaining-build-logs-with-msbuild?view=vs-2017#verbosity-settings) message, Warning and Exception are ok, do you have same issue?

[derhally]

@tonerdo @derhally I did some tests I cannot show LogInformation/LogVerbose(https://docs.microsoft.com/en-us/visualstudio/msbuild/obtaining-build-logs-with-msbuild?view=vs-2017#verbosity-settings) message, Warning and Exception are ok, do you have same issue?

So, I completely glossed over that I didn't switch CoverageResultTask to use the logger instead of console. I fixed that.

It seems if you use "dotnet test" you need to specify -v n to see the coverage report and that's even with the MessageImportance set to High. I'm not sure if that is the expected behavior. I would think that people would want to see output by default. This is very odd.

[MarcoRossignoli]

It seems if you use "dotnet test" you need to specify -v n to see the coverage report and that's even with the MessageImportance set to High. I'm not sure if that is the expected behavior. I would think that people would want to see output by default. This is very odd.

For now I think we should use Console.WriteLine and use logger only for "debugging" purpouse.
The odd thing is that if I try to add for instance

  _logger.LogInformation("TEST");
  _logger.LogWarning("WARNING");

and run build

 msbuild build.proj /verbosity:diagnostic

I get only warning notification

...
  Build completed. (TaskId:7)
   (TaskId:7)
D:\git\coverlet\build\Debug\coverlet.msbuild.targets(21,5): warning : WARNING [D:\git\coverlet\test\coverlet.core.tests\coverlet.core.tests.csproj] [D:\git\coverlet\build.proj]
  Test run for D:\git\coverlet\test\coverlet.core.tests\bin\Debug\netcoreapp2.0\coverlet.core.tests.dll(.NETCoreApp,Version=v2.0) (TaskId:7)
  Microsoft (R) Test Execution Command Line Tool Version 16.0.0-preview-20181205-02 (TaskId:7)
  Copyright (c) Microsoft Corporation.  All rights reserved. (TaskId:7)
   (TaskId:7)
...

I dunno why information is not shown @tonerdo do you have some idea? Maybe you've more experience with msbuild.

[derhally]

An option is to use Console for the Logger.Information and still use the MSBuild logger for Error and Warning so that those go through the build system

[MarcoRossignoli]

An option is to use Console for the Logger.Information and still use the MSBuild logger for Error and Warning so that those go through the build system

Could be a breaking change, because until today coverlet users expect console output with percentace, if we use build system log a "quiet" verbosity will suppress all output.

[MarcoRossignoli]

@derhally are you able to complete this PR if not I could do last minor open changes with no problem(if you're busy, you already did a great work on this)!
@tonerdo I think that logging could help in some of open issues what do you think?I mean we should add verbose logging in some parts(inclusion exclusion filter, file instrumenting mainly).

[derhally]

@MarcoRossignoli which track would you prefer, should the CovverageResultTask use

1. Console.WriteLine as before
2. Use ILogger api and change MSBuildLogger implementation to log to console?
3. Use ILogger and leave the current implementation of MSBuildLogger

Either way, the behavior would be same as before.

[MarcoRossignoli]

• I would use Console.WriteLine as before because that message is not an infrastructure message, I mean we want to see that message with or without swich applied(verbose etc...)
• And use msbuild logger on LogInformation with comment Added logging to Coverage to help with debugging #341 (comment)

[MarcoRossignoli]

@tonerdo LGTM!
Thank's again @derhally!

[tonerdo]

@tonerdo I think that logging could help in some of open issues what do you think?I mean we should add verbose logging in some parts(inclusion exclusion filter, file instrumenting mainly).

@MarcoRossignoli totally agree. I'm thinking we could add a diag (or similar) flag to turn on verbose logging for debugging purposes

[tonerdo]

Thank you @derhally!

[MarcoRossignoli]

@MarcoRossignoli totally agree. I'm thinking we could add a diag (or similar) flag to turn on verbose logging for debugging purposes

Seems that for now we can use dotnet test /p:CollectCoverage=true -v:n #341 (comment) I did some test with:
dotnet test "C:\git\coverlet\test\coverlet.core.tests\coverlet.core.tests.csproj" -c Debug /p:CollectCoverage=true /p:CoverletOutputFormat=opencover /p:Include=[coverlet.*]* -v:n

The worst part is that we get output also for others, but better than nothing for now.