.NET Core Tool Support

[StrangeWill]

Any plans to support the new "dotnet" command? Considering dnx command support is dropped and the new tooling should allow for better self-configuration over the old DNX method found here: https://github.com/OpenCover/opencover/wiki/DNX-Support

[sawilde]

Currently not yet - the runtime does not fully support the Profiling API and to also fully support the platform would require us to build the profiler virtually from scratch to run on linux platform, something I do not have the bandwidth for. If you build your libraries as PCL I believe you can also run them on .NET 4.5 etc on windows and get coverage from OpenCover assuming your tooling allows that.

I only develop/enhance OpenCover for my needs and I currently do not have the need; It doesn't mean someone else can't do the work but it probably won't be me in the near future.

[haythem]

Hi @StrangeWill,

I've managed to get it running using the following command :
opencover.console.exe -register:user -target:"C:/Program Files/dotnet/dotnet.exe" -targetargs:"test test/MyProject.Test" -output:"coverage.xml"

Make sure you have xunit-runner on your test project. Please let me know if you encounter any problems.

[StrangeWill]

@haythem Awesome! Thanks I'll try that out later this week.

[tmds]

I tried

c:\Users\tmds\AppData\Local\Apps\OpenCover\OpenCover.Console.exe "-target:C:\Program Files\dotnet\dotnet.exe"  -targetargs:test -register:user -filter:"+[*]* -[xunit*]*" -output:coverage.xml

This generates a report, but the report shows zero coverage for all the code.
What could be wrong?

[snookerfly]

I had this running with dotnet RC2 too, but when upgrading to final it stopped working on my CI machine (Windows 2012 R2), but still works on developer machines (Windows 7).

Any ideas anyone?

[sawilde]

What does it say in the XML file for the reason why an assembly of interest was skipped?

[snookerfly]

Nothing. The assembly was not skipped, you just get an entry with line / branch coverage 0.

Interestingly enough it works when using the oldStyle switch. I also installed VS 2015 Update 3 on our CI server but still the same issue exists.

[StrangeWill]

dotCover is also having the same issue since 1.0.0 came out, wonder if the change that broke them both is related...

[snookerfly]

might be. only strange thing is that it's only occuring on W2k12R2 (at least that's where it's happening for me). I'll check W10 tonight.

[sawilde]

Interestingly enough it works when using the oldStyle switch.

Ah that explains it - OpenCover needs to hook into a class in mscorlib to work around a security issue with pinvoke - the class in question in .NET core is no longer mscorlib so OpenCover can't hook it anymore - The -oldstyle switch does not use that class but you may encounter security issues especially around 'AssemblyAllowsPartialTrust...'

see #595

[snookerfly]

and it also happens on W10.

[sawilde]

and it also happens on W10.

it's not an OS issue it's what they've done to the structure - since there is a workaround I have not made it high on my agenda.

[tmds]

There are two aspects to this issue:

• make it work on .NET Core
• integrate with .NET Core

From what I read here, if you pass -oldstyle it should work.
The second aspect is supporting OpenCover as a dotnet tool. This means you can add it in the project.json tools section, pull it as a dependency and invoke it using the dotnet cli (like Microsoft.EntityFrameworkCore.Tools).