Release/2.0.0 - Add tests for EventArgs serialization (#25940)

[ViktorHofer]

Relates to https://github.com/dotnet/corefx/issues/25930

• Add tests for EventArgs serialization

• Add EventArgs equality check as the type doesn't provide its own check

[danmoseley]

Tests pending on dotnet/coreclr#15686

[ViktorHofer]

Triggered a coreclr 2.0 build. waiting for maestro PR...

[ViktorHofer]

@dotnet-bot test this please

[ViktorHofer]

@dotnet/dnceng some of these legs show that they succeeded but have failed tests. wrong status shown? E.g. Windows x86 Release Build

[danmoseley]

@dotnet-bot test this please

[MattGal]

@ViktorHofer thanks for bringing this to @dnceng 's attention, I'll take a look and file an internal issue if needed if I find anything actionable and broken.

[MattGal]

@ViktorHofer I spent some time looking at this. Unfortunately, as you've restarted the build I can't see what the results view (mc.dot.net) looked like when you first raised the issue, but in either case the windows tests are reliably failing in the binary serialization tests, i.e.
https://mc.dot.net/#/user/ViktorHofer/pr~2Fjenkins~2Fdotnet~2Fcorefx~2Frelease~2F2.0.0~2F/test~2Ffunctional~2Fcli~2F/5e42ac4b84d5061eba00ebd45ccc34338e713724/workItem/System.Runtime.Serialization.Formatters.Tests .

The test fails on every platform actually. If you can capture a screen shot of what you're seeing if this happens again that'd be awesome, as I'd expect to have seen this test fail uniformly (every run in your PR seems to have it failing)

[ViktorHofer]

Yes I expected nearly all legs to fail as there was a bug in the test code. Unfortunately the build was restarted today but I still have the link to the leg: https://ci3.dot.net/job/dotnet_corefx/job/release_2.0.0/job/windows-TGroup_netfx+CGroup_Release+AGroup_x86+TestOuter_false_prtest/66/

Is that enough?

[ViktorHofer]

@dotnet/dnceng this time a failing OSX x64 Debug Build leg:

https://ci3.dot.net/job/dotnet_corefx/job/release_2.0.0/job/osx-TGroup_netcoreapp+CGroup_Debug+AGroup_x64+TestOuter_false_prtest/73/consoleText

ERROR: Error cloning remote repo 'origin'
hudson.plugins.git.GitException: Could not init /Users/dotnet-bot/j/workspace/dotnet_corefx/release_2.0.0/osx-TGroup_netcoreapp+CGroup_Debug+AGroup_x64+TestOuter_false_prtest

[ViktorHofer]

@dotnet-bot test OSX x64 Debug Build