Support OpenCover on MacOS

[whigley]

I run nunit test on MacOS fine using mono command, but when I try to do the same thing with Open Cover I get this error:

Command Used:
mono "/Users/xxx/build_bin/opencover.4.5.3207/OpenCover.Console.exe" -target:"/Users/xxx/build_bin/NUnit-2.6.3/bin/nunit-console-x86.exe" -targetargs:"-nologo -noshadow ${WORKSPACE}/src/MyApp.PSC/App.PSC.Common.UnitTests/bin/Release/App.PSC.Common.UnitTests.dll" -filter:"+:* -:UnitTests" -register:/Users/xxx/build_bin/opencover.4.5.3207/x86/OpenCover.Profiler.dll: -mergebyhash -output:${WORKSPACE}/CodeCoverage.xml

Error:
The files /Users/pearson-cm/JenkinsX/workspace/DryRun-i/regsvr32.exe, /s, and /Users/pearson-cm/build_bin/opencover.4.5.3207/x86\OpenCover.Profiler.dll do not exist.

If I remove the -register, then it works but no coverage report is created.

What am I doing wrong???

[sawilde]

You are not doing anything wrong - OpenCover is only for Windows as it uses the Profiler API which is not supported on Linux/MacOS.

To get coverage on Linux/MacOS when using mono you should have a look at monocov

[whigley]

Thank you for your response.
Any plans to have Mac OS support?

[molnargab]

I guess mostly it would involve implementing a new profiler for Mono.
Actually this post looks quite promising.
There could be other dependencies as well, like #220.

Of course, installers, MSBuild tasks, etc. for OC would be void for Linux and OS X.
I'm not sure if someone would pick this up, but sounds like a fun project for one with some Linux affinity.

[sawilde]

@wabuhigleh I haven't really thought about it as mono already has a coverage tool.

@molnargab those hooks look interesting so then it boils down to interaction between the profiler that is hooked into the process running under mono and the host.

I'll mark it as a feature request since there is a potential avenue of attack; I am currently looking at the windows store app support.

[whigley]

It is undocumented, hard to use, and not as good as OpenCover.
We are currently developing apps using C# for Windows 8, iOS, and Android (all using Xamarin). I am using OpenCover with Jenkins for all platforms except iOS (NUnit for all), it will be great to have one coverage tool for all.

[sawilde]

Well it's on the feature list perhaps someone will pick it up.

[whigley]

I managed to have Jenkins to copy the unit test binaries to a remote shared windows drive, so that anther Jenkins job will run OpenCover (on Windows) against MacOS compiled binaries. I thought I made it .. ,but OpenCover was seeking PDB files which were missing. After some investigation, I found that Xamarin mdtool compiler produces MDB files (not PDB files which are generated on Windows). I am seeking away to convert MDB to PDB .. or any other alternate solution. Any suggestions?

[molnargab]

Nice workaround.
If there isn't already such converter available, I'd start with creating a tool with Cecil to read the assembly with the MDB symbols and write it to another with PDB. There are some hints on the wiki, you'll have to use the MdbSymbolReaderProvider and the PdbSymbolWriterProvider. Keep us posted how this works out.

Actually it should be much easier to add MDB support first, as OpenCover already uses Mono.Cecil for PDB parsing. Cecil has MDB support as well.

[sawilde]

We could of course also investigate using OpenCover to consume MDB files - as long as we can pull out the same info for the instrumentation. Since the interface is the same it should be a straight substitution.

Could inject ISymbolReaderProvider into CecilSymbolReader and use that to pull the correct provider for the pdb/mdb supplied based on file extension.

[sawilde]

@wabuhigleh How are you running the compiled assemblies do you have a sample so we can check we are doing the same thing?

[whigley]

The compiled assemblies are generated by Xamarin command-line tool: mdtool
I have the binaries for the unit test project DLLs and MDBs .. is that what you are seeking?