Instrumenting coverage tool for .net (framework 2.0+ and core) and Mono, reimplemented and extended almost beyond recognition from dot-net-coverage, plus a set of related utilities for processing the results from this and from other programs producing similar output formats.
Start with the Quick Start guide
The latest releases can be downloaded from releases, but the easiest (and most automated) way is through the nuget packages.
For Mono, .net framework and .net core, except as noted
AltCover, a command-line tool for recording code coverage (including dotnet and global tool versions)dotnet test integration
As the name suggests, it's an alternative coverage approach. Rather than working by hooking the .net profiling API at run-time, it works by weaving the same sort of extra IL into the assemblies of interest ahead of execution. This means that it should work pretty much everywhere, whatever your platform, so long as the executing process has write access to the results file. You can even mix-and-match between platforms used to instrument and those under test.
In particular, while instrumenting .net core assemblies "just works" with this approach, it also supports Mono, as long as suitable .mdb (or .pdb, in recent versions) symbols are available. One major limitation here is that the .mdb format only stores the start location in the source of any code sequence point, and not the end; consequently any nicely coloured reports that take that information into account may show a bit strangely.
Back in 2010, the new .net version finally removed the deprecated profiling APIs that the free NCover 1.5.x series relied upon. The first version of AltCover was written to both fill a gap in functionality, and to give me an excuse for a ground-up F# project to work on. As such, it saw real production use for about a year and a half, until OpenCover reached a point where it could be used for .net4/x64 work (and I could find time to adapt everything downstream that consumed NCover format input).
Fast forwards to autumn 2017, and I get the chance to dust the project off, with the intention of saying that it worked on Mono, too -- and realise that it's déja vu all over again, because .net core didn't yet have profiler based coverage tools either, and the same approach would work there as well.
On old-fashioned .net framework, the ProcessExit event handling window of ~2s is sufficient for processing significant bodies of code under test (several 10s of kloc, as observed in production back in the '10-'11 timeframe); under dotnet testthe vstest.console process imposes a 100ms guillotine, even though .net Core imposes no time-limit of its own. This is about enough time to fill in an NCover report for a program of no more than 1kloc, hence the development of a "write it all promptly to file and post-process" Runner mode. With version 5.3 and above, the dotnet test integration now hooks the VSTest in-process data collection, allowing an indefinite window to write collected data from memory, thus removing the file I/O bottleneck.
Under Mono on non-Windows platforms the default values of --debug:full or --debug:pdbonly generate no symbols from F# projects -- and without symbols, such assemblies cannot be instrumented. Unlike with C# projects, where the substitution appears to be automatic, to use the necessary --debug:portable option involves explicitly hand editing the old-school .fsproj file to have <DebugType>portable</DebugType>.
See the Wiki page for details
See the current project for details