[BUG] Coverlet Nightly Crashing when merging JSON results

[pinkfloydx33]

Describe the bug
When running the coverlet nightly builds the generation of results fails when combining multiple test runs using JSON format. Individual runs generate reports successfully. The exception thrown is:

/home/AzDevOps/.nuget/packages/coverlet.msbuild/6.0.1-preview.31.g0db8de77cb/build/coverlet.msbuild.targets(72,5): error : Deserialization of types without a parameterless constructor, a singular parameterized constructor, or a parameterized constructor annotated with 'JsonConstructorAttribute' is not supported. Type 'Coverlet.Core.Method'. Path: $['MyProject.Auth.dll']['/datadisks/disk1/work/1/s/src/MyProject.Auth/Utils/AuthExtensions.cs']['MyProject.Auth.Utils.AuthExtensions']['System.Threading.Tasks.Task MyProject.Auth.Utils.AuthExtensions::ClearRolesForUser(MyProject.Auth.Services.IExternalAuthService,System.String,System.Threading.CancellationToken)'] | LineNumber: 4 | BytePositionInLine: 204. [/datadisks/disk1/work/1/s/test/MyProject.Distributed.Extensions.Tests/MyProject.Distributed.Extensions.Tests.csproj]
/home/AzDevOps/.nuget/packages/coverlet.msbuild/6.0.1-preview.31.g0db8de77cb/build/coverlet.msbuild.targets(72,5): error :    at System.Text.Json.ThrowHelper.ThrowNotSupportedException(ReadStack& state, Utf8JsonReader& reader, NotSupportedException ex) [/datadisks/disk1/work/1/s/test/MyProject.Distributed.Extensions.Tests/MyProject.Distributed.Extensions.Tests.csproj]
/home/AzDevOps/.nuget/packages/coverlet.msbuild/6.0.1-preview.31.g0db8de77cb/build/coverlet.msbuild.targets(72,5): error :    at System.Text.Json.ThrowHelper.ThrowNotSupportedException_DeserializeNoConstructor(Type type, Utf8JsonReader& reader, ReadStack& state) [/datadisks/disk1/work/1/s/test/MyProject.Distributed.Extensions.Tests/MyProject.Distributed.Extensions.Tests.csproj]
/home/AzDevOps/.nuget/packages/coverlet.msbuild/6.0.1-preview.31.g0db8de77cb/build/coverlet.msbuild.targets(72,5): error :    at System.Text.Json.Serialization.Converters.ObjectDefaultConverter`1.OnTryRead(Utf8JsonReader& reader, Type typeToConvert, JsonSerializerOptions options, ReadStack& state, T& value) [/datadisks/disk1/work/1/s/test/MyProject.Distributed.Extensions.Tests/MyProject.Distributed.Extensions.Tests.csproj]
/home/AzDevOps/.nuget/packages/coverlet.msbuild/6.0.1-preview.31.g0db8de77cb/build/coverlet.msbuild.targets(72,5): error :    at System.Text.Json.Serialization.JsonConverter`1.TryRead(Utf8JsonReader& reader, Type typeToConvert, JsonSerializerOptions options, ReadStack& state, T& value) [/datadisks/disk1/work/1/s/test/MyProject.Distributed.Extensions.Tests/MyProject.Distributed.Extensions.Tests.csproj]
/home/AzDevOps/.nuget/packages/coverlet.msbuild/6.0.1-preview.31.g0db8de77cb/build/coverlet.msbuild.targets(72,5): error :    at System.Text.Json.Serialization.JsonDictionaryConverter`3.OnTryRead(Utf8JsonReader& reader, Type typeToConvert, JsonSerializerOptions options, ReadStack& state, TDictionary& value) [/datadisks/disk1/work/1/s/test/MyProject.Distributed.Extensions.Tests/MyProject.Distributed.Extensions.Tests.csproj]
/home/AzDevOps/.nuget/packages/coverlet.msbuild/6.0.1-preview.31.g0db8de77cb/build/coverlet.msbuild.targets(72,5): error :    at System.Text.Json.Serialization.JsonConverter`1.TryRead(Utf8JsonReader& reader, Type typeToConvert, JsonSerializerOptions options, ReadStack& state, T& value) [/datadisks/disk1/work/1/s/test/MyProject.Distributed.Extensions.Tests/MyProject.Distributed.Extensions.Tests.csproj]
/home/AzDevOps/.nuget/packages/coverlet.msbuild/6.0.1-preview.31.g0db8de77cb/build/coverlet.msbuild.targets(72,5): error :    at System.Text.Json.Serialization.JsonDictionaryConverter`3.OnTryRead(Utf8JsonReader& reader, Type typeToConvert, JsonSerializerOptions options, ReadStack& state, TDictionary& value) [/datadisks/disk1/work/1/s/test/MyProject.Distributed.Extensions.Tests/MyProject.Distributed.Extensions.Tests.csproj]
/home/AzDevOps/.nuget/packages/coverlet.msbuild/6.0.1-preview.31.g0db8de77cb/build/coverlet.msbuild.targets(72,5): error :    at System.Text.Json.Serialization.JsonConverter`1.TryRead(Utf8JsonReader& reader, Type typeToConvert, JsonSerializerOptions options, ReadStack& state, T& value) [/datadisks/disk1/work/1/s/test/MyProject.Distributed.Extensions.Tests/MyProject.Distributed.Extensions.Tests.csproj]
/home/AzDevOps/.nuget/packages/coverlet.msbuild/6.0.1-preview.31.g0db8de77cb/build/coverlet.msbuild.targets(72,5): error :    at System.Text.Json.Serialization.JsonDictionaryConverter`3.OnTryRead(Utf8JsonReader& reader, Type typeToConvert, JsonSerializerOptions options, ReadStack& state, TDictionary& value) [/datadisks/disk1/work/1/s/test/MyProject.Distributed.Extensions.Tests/MyProject.Distributed.Extensions.Tests.csproj]
/home/AzDevOps/.nuget/packages/coverlet.msbuild/6.0.1-preview.31.g0db8de77cb/build/coverlet.msbuild.targets(72,5): error :    at System.Text.Json.Serialization.JsonConverter`1.TryRead(Utf8JsonReader& reader, Type typeToConvert, JsonSerializerOptions options, ReadStack& state, T& value) [/datadisks/disk1/work/1/s/test/MyProject.Distributed.Extensions.Tests/MyProject.Distributed.Extensions.Tests.csproj]
/home/AzDevOps/.nuget/packages/coverlet.msbuild/6.0.1-preview.31.g0db8de77cb/build/coverlet.msbuild.targets(72,5): error :    at System.Text.Json.Serialization.JsonDictionaryConverter`3.OnTryRead(Utf8JsonReader& reader, Type typeToConvert, JsonSerializerOptions options, ReadStack& state, TDictionary& value) [/datadisks/disk1/work/1/s/test/MyProject.Distributed.Extensions.Tests/MyProject.Distributed.Extensions.Tests.csproj]
/home/AzDevOps/.nuget/packages/coverlet.msbuild/6.0.1-preview.31.g0db8de77cb/build/coverlet.msbuild.targets(72,5): error :    at System.Text.Json.Serialization.JsonConverter`1.TryRead(Utf8JsonReader& reader, Type typeToConvert, JsonSerializerOptions options, ReadStack& state, T& value) [/datadisks/disk1/work/1/s/test/MyProject.Distributed.Extensions.Tests/MyProject.Distributed.Extensions.Tests.csproj]
/home/AzDevOps/.nuget/packages/coverlet.msbuild/6.0.1-preview.31.g0db8de77cb/build/coverlet.msbuild.targets(72,5): error :    at System.Text.Json.Serialization.JsonConverter`1.ReadCore(Utf8JsonReader& reader, JsonSerializerOptions options, ReadStack& state) [/datadisks/disk1/work/1/s/test/MyProject.Distributed.Extensions.Tests/MyProject.Distributed.Extensions.Tests.csproj]
/home/AzDevOps/.nuget/packages/coverlet.msbuild/6.0.1-preview.31.g0db8de77cb/build/coverlet.msbuild.targets(72,5): error :    at System.Text.Json.JsonSerializer.ReadFromSpan[TValue](ReadOnlySpan`1 utf8Json, JsonTypeInfo jsonTypeInfo, Nullable`1 actualByteCount) [/datadisks/disk1/work/1/s/test/MyProject.Distributed.Extensions.Tests/MyProject.Distributed.Extensions.Tests.csproj]
/home/AzDevOps/.nuget/packages/coverlet.msbuild/6.0.1-preview.31.g0db8de77cb/build/coverlet.msbuild.targets(72,5): error :    at System.Text.Json.JsonSerializer.ReadFromSpan[TValue](ReadOnlySpan`1 json, JsonTypeInfo jsonTypeInfo) [/datadisks/disk1/work/1/s/test/MyProject.Distributed.Extensions.Tests/MyProject.Distributed.Extensions.Tests.csproj]
/home/AzDevOps/.nuget/packages/coverlet.msbuild/6.0.1-preview.31.g0db8de77cb/build/coverlet.msbuild.targets(72,5): error :    at System.Text.Json.JsonSerializer.Deserialize[TValue](String json, JsonSerializerOptions options) [/datadisks/disk1/work/1/s/test/MyProject.Distributed.Extensions.Tests/MyProject.Distributed.Extensions.Tests.csproj]
/home/AzDevOps/.nuget/packages/coverlet.msbuild/6.0.1-preview.31.g0db8de77cb/build/coverlet.msbuild.targets(72,5): error :    at Coverlet.Core.Coverage.GetCoverageResult() in /_/src/coverlet.core/Coverage.cs:line 317 [/datadisks/disk1/work/1/s/test/MyProject.Distributed.Extensions.Tests/MyProject.Distributed.Extensions.Tests.csproj]
/home/AzDevOps/.nuget/packages/coverlet.msbuild/6.0.1-preview.31.g0db8de77cb/build/coverlet.msbuild.targets(72,5): error :    at Coverlet.MSbuild.Tasks.CoverageResultTask.Execute() in /_/src/coverlet.msbuild.tasks/CoverageResultTask.cs:line 87 [/datadisks/disk1/work/1/s/test/MyProject.Distributed.Extensions.Tests/MyProject.Distributed.Extensions.Tests.csproj]

Depending on the order in which I run the projects, the first line of the message will include multiple Type and/or method names

To Reproduce
Run coverlet nightly build (6.0.1-preview.31.g0db8de77cb) against a project and use json output format. Then, run coverlet against another project (or even the same one!) with the MergeWith option.

dotnet test --configuration Release --logger "console" --logger xunit -p:CollectCoverage=true -p:CoverletOutputFormat="json" -p:CoverageRoot="${PWD}/../Coverage" -p:MergeWith="${PWD}/../Coverage/coverage.json" 

Expected behavior
Coverlet does not crash

Actual behavior
Coverlet crashes with the above exception

Configuration (please complete the following information):
Please provide more information on your .NET configuration:
* Which coverlet package and version was used? 6.0.1-preview.31.g0db8de77cb (also crashes on 6.0.1-preview.26.g71c202b19e)
* Which version of .NET is the code running on? .NET7 but .NET SDK 8.0.0 is installed and active
* What OS and version, and what distro if applicable? Windows 11 x64, Ubuntu 22.04
* What is the architecture (x64, x86, ARM, ARM64)? x64
* Do you know whether it is specific to that configuration? Occurs on at least two configurations mentioned

Additional context
Works fine with package versions 6.0.0

[Bertk]

Thanks for reporting 🙏

Please use the Packages (ZIP file) from PR build and try the MergeWith operation again.

Please share the results.

see also https://stackoverflow.com/questions/72268018/jsonconstructor-fails-on-ienumerable-property

[pinkfloydx33]

I will try later today if I can, otherwise it will likely need to wait until Monday.

Thanks for looking into this.

[pinkfloydx33]

@Bertk @MarcoRossignoli @daveMueller

Sorry for the delay. I just tested with the packages from the feed linked above and it does not correct the issue:

D:\Packages\nuget\coverlet.msbuild\6.0.1-preview.34.gfba427ba33\build\coverlet.msbuild.targets(72,5): error : Deserial
ization of types without a parameterless constructor, a singular parameterized constructor, or a parameterized constru
ctor annotated with 'JsonConstructorAttribute' is not supported. Type 'Coverlet.Core.Method'.

I think this fix only works for .NET8+ (from this documentation):

In .NET 7 and earlier versions, the [JsonConstructor] attribute can only be used with public constructors.

---

I assume this means Coverlet's target framework and not my project's. Coverlet looks to be running on net6.0:

coverlet/src/coverlet.core/coverlet.core.csproj

Line 5 in 1981476

<TargetFrameworks>netstandard2.0;net6.0</TargetFrameworks>

coverlet/src/coverlet.msbuild.tasks/coverlet.msbuild.tasks.csproj

Line 5 in 1981476

<TargetFrameworks>netstandard2.0;net6.0</TargetFrameworks>

coverlet/src/coverlet.collector/coverlet.collector.csproj

Line 3 in 1981476

<TargetFrameworks>netstandard2.0;net6.0</TargetFrameworks>

coverlet/src/coverlet.console/coverlet.console.csproj

Line 5 in 1981476

<TargetFramework>net6.0</TargetFramework>

---

I think another option would be updating the version of S.T.J to the 8.0.x band which should be compatible with .NET6

coverlet/src/coverlet.core/coverlet.core.csproj

Line 16 in 1981476

<PackageReference Include="System.Text.Json" VersionOverride="6.0.9"/>

[Bertk]

@pinkfloydx33 Could you please check the package from draft build

If this does not resolve the issue, I will update System.Text.Json version to 8.0.1.

[pinkfloydx33]

@Bertk I will test this morning and report back

[pinkfloydx33]

@Bertk I can confirm that the packages from the draft build you linked are working as expected

[pinkfloydx33]

@Bertk thanks! do you know when this will make it into the nightly builds?