Add support for `runtimeconfig.template.json`

[dotMorten]

If I add RuntimeHostConfigurationOption to the benchmark project like this:

<ItemGroup>
    <RuntimeHostConfigurationOption Include="System.Runtime.Loader.UseRidGraph" Value="true" />
  </ItemGroup>

The built project will have this added to [appname].runtimeconfig.json:

{
  "runtimeOptions": {
     "configProperties": {
        "System.Runtime.Loader.UseRidGraph": true
     }
  }
}

This is important to be able to deal with this breaking change in .NET 8:

https://learn.microsoft.com/en-us/dotnet/core/compatibility/deployment/8.0/rid-asset-list#recommended-action

However, the generated project does not copy this setting over, so the resulting project will not get the correct value injected into its runtimeconfig.json.
An alternative way is to add a runtimeconfig.template.json file with the above json, but again, the generated project will not pick this up.

Perhaps

BenchmarkDotNet/src/BenchmarkDotNet/Toolchains/CsProj/CsProjGenerator.cs

Line 26 in ece5ccf

private static readonly ImmutableArray<string> SettingsWeWantToCopy = new[]

needs RuntimeHostConfigurationOption added, and also a way to make sure runtimeconfig.template.json files are copied as well.

[timcassell]

Reopening for someone to add support for runtimeconfig.template.json.

[keegan-caruso]

@timcassell It looks like RuntimeHostConfigurationOption is copied over to the autogenerated csproj as expected for a default job.

It is not copied over if using a native AOT toolchain.

Would you like to use this issue to also track that, or would you like me to open a new issue for this?

[timcassell]

That's surprising, it shares the same csproj generator as the other toolchains. I don't think we need a separate issue, if you want to send a PR and link it to your comment here.