Uncovered lines in .NET 8

[samuel-utbult-oborgen]

Describe the bug
When creating a record inheriting another record in a .NET 8 project, the initial line containing public record is reported as not covered by tests even though the record is used in the tests.

To Reproduce

1. Create a record.
2. Create another record inheriting that record.
3. Create a test using the second record.
4. Run the test with test coverage.
5. The line containing public record on the second record is reported as not tested.

Here is an example project showcasing the problem: https://github.com/samuel-utbult-oborgen/coverlet-missing-line-example

Expected behavior
The uncovered line should either be covered or ignored.

Actual behavior
The line is reported as uncovered.

Configuration
The following environment it used:

• coverlet 6.0.0
• .NET 8
• macOS Sonoma 14.0
• x64
• I have not encountered this problem in .NET 7 but coverlet 3.2.0 seems to have the same problem.

[gburkecw]

we are are having this issue since the MSBUILD 17.8 update, but for .NET 7 projects. GH Actions updated their latest agents to use MSBUILD 17.8 and we started seeing this issue.

For now as a workaround we are building with older agents that still have MSBuild 17.7, but I'm also going to see if I can specify an older language version in the csproj or something.

Still, it seems like this might prevent us from updating to .NET 8

[samuel-utbult-oborgen]

I'm also going to see if I can specify an older language version in the csproj or something.

I can confirm that this does not work at least when it comes to updating to .NET 8. My computer has .NET 8 installed but all .csproj files in the project I'm working on have <TargetFramework>net7.0</TargetFramework> specified and the coverage problem is still present.

[Bertk]

Hi, thank you for the information but I can not reproduce the error using the latest preview.

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <TargetFramework>net8.0</TargetFramework>
    <LangVersion>12.0</LangVersion>
    <ImplicitUsings>disable</ImplicitUsings>
    <Nullable>enable</Nullable>

    <IsPackable>false</IsPackable>
    <IsTestProject>true</IsTestProject>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.8.0" />
    <PackageReference Include="xunit" Version="2.6.2" />
    <PackageReference Include="xunit.runner.visualstudio" Version="2.5.4">
      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
      <PrivateAssets>all</PrivateAssets>
    </PackageReference>
    <PackageReference Include="coverlet.collector" Version="6.0.1-preview.25.g21d3964f03">
      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
      <PrivateAssets>all</PrivateAssets>
    </PackageReference>
  </ItemGroup>

  <ItemGroup>
    <ProjectReference Include="..\ExampleProject\ExampleProject.csproj" />
  </ItemGroup>

</Project>

C:\GitHub\coverlet-missing-line-example>dotnet --info
.NET SDK:
 Version:           8.0.100
 Commit:            57efcf1350
 Workload version:  8.0.100-manifests.71b9f198

Runtime Environment:
 OS Name:     Windows
 OS Version:  10.0.22631
 OS Platform: Windows
 RID:         win-x64
 Base Path:   C:\Program Files\dotnet\sdk\8.0.100\

.NET workloads installed:
 Workload version: 8.0.100-manifests.71b9f198
There are no installed workloads to display.

Host:
  Version:      8.0.0
  Architecture: x64
  Commit:       5535e31a71

.NET SDKs installed:
  6.0.417 [C:\Program Files\dotnet\sdk]
  7.0.404 [C:\Program Files\dotnet\sdk]
  8.0.100 [C:\Program Files\dotnet\sdk]

.NET runtimes installed:
  Microsoft.AspNetCore.App 6.0.25 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 7.0.14 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 8.0.0 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 6.0.15 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 6.0.25 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 7.0.14 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 8.0.0 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.WindowsDesktop.App 6.0.15 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 6.0.25 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 7.0.14 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 8.0.0 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

Other architectures found:
  x86   [C:\Program Files (x86)\dotnet]
    registered at [HKLM\SOFTWARE\dotnet\Setup\InstalledVersions\x86\InstallLocation]

Environment variables:
  Not set

global.json file:
  Not found

Learn more:
  https://aka.ms/dotnet/info

Download .NET:
  https://aka.ms/dotnet/download

C:\GitHub\coverlet-missing-line-example>dotnet msbuild --version
MSBuild version 17.8.3+195e7f5a3 for .NET
17.8.3.51904

Per the published support rules, the minimum Visual Studio and MSBuild version for each new major release is updated with a one quarter delay. For the .NET 8 release, 8.0.100 requires version 17.7 to be loaded but only supports targeting .NET 7 in that version. To target net8.0, you must use version 17.8 or later.

[samuel-utbult-oborgen]

I have updated the example. Could you try the following?

1. Install the tool dotnet-reportgenerator-globaltool.
2. Run the test with test coverage as before.
3. Copy the path to the generated .info file.
4. Run this command: dotnet tool run reportgenerator -reports:[paste the path here] -targetdir:coverage/html
5. Open coverage/html/index.html in a web browser.
6. Click on InheritedRecord.
7. Line 3 is reported as uncovered, just as the .info file described.

[Bertk]

Thanks I will check it tomorrow.

By the way, please use this command to generate a valid .gitignore file for the example git repository:
dotnet new gitignore -force

[Bertk]

The coverlet.runsetting excludes generated code and therefore uncovered line is removed.

dotnet test --collect:"XPlat Code Coverage;Format=lcov" --settings coverlet.runsettings

<?xml version="1.0" encoding="utf-8"?>
<RunSettings>
  <DataCollectionRunSettings>
    <DataCollectors>
      <DataCollector friendlyName="XPlat code coverage">
        <Configuration>
          <ExcludeByAttribute>Obsolete,GeneratedCodeAttribute,CompilerGeneratedAttribute</ExcludeByAttribute>
        </Configuration>
      </DataCollector>
    </DataCollectors>
  </DataCollectionRunSettings>
</RunSettings>

Please check whether this is an acceptable solution. This will also remove async methods from the coverage results (more details #1561).

[samuel-utbult-oborgen]

I can confirm the proposed solution removes the uncovered line in InheritedRecord. However, the tradeoff of not covering asynchronous methods is not acceptable in my situation as the project I am aiming to upgrade to .NET 8 consists in a large part of asynchronous methods. The branch exclude_generated_code in my example project showcases this problem.