Coverlet.Core.Instrumentation.Tracker. runtime Type created in production assembly

[apsthisdev]

I have simple .NET core assembly

MyAssembly.csproj (src)

MyAssemblyTest.csproj (test)

• MyAssemblyTest References coverlet to generate the test reports.
• MyAssemblyTest references the MyAssembly.csproj
• Defines MSTest that validates MyAssembly types using reflection.

After running the tests I noticed that the coverlet creates a runtime type in MyAssembly and this assembly which does not reference coverlet at all !

Coverlet.Core.Instrumentation.Tracker.MyAssembly_563b4785-5c80-4b10-82c6-9057f0038f04

Why is coverlet creating a tracker inside a production assembly that does not references coverlet at the first place ?

[MarcoRossignoli]

Coverlet injects a static class inside assembly during instrumentation. This class contains method to record the hint. We refer to this method inside user instrumented types. After the instrumentation we "rollback" to the original dlls(original ones are saved in a tmp dir).
Hits are collected in a in memory array and persisted to a file system on process exits.

Why is coverlet creating a tracker inside a production assembly that does not references coverlet at the first place ?

We cannot add dependency to user assembly or we risk to break the real code(our dependencies could influence behavior loading external and not expected assemblies). We simply inject "some helper" class but we don't "inject" any dependency.
On runtime we rely on BCL(base class library) primitive types(array, mutex, files).

[MarcoRossignoli]

This is the current injected tracker https://github.com/coverlet-coverage/coverlet/blob/master/src/coverlet.core/Instrumentation/ModuleTrackerTemplate.cs

[apsthisdev]

Thanks for the explanation, so after the instrumentation the original dlls will not have these trackers. Can we have CompilerGeneratedAttribute on them so that other type inspection algorithms can ignore these trackers ?

[MarcoRossignoli]

I think it's possible and should not have impact.
Thanks for the advice.