[Feature] Add support for keyed services

[martintmk]

Pull Request

The issue or feature being addressed

#1874

Details on the issue fix or feature implementation

This PR adds support for keyed services into Polly.

Confirm the following

• I started this PR by branching from the head of the default branch
• I have targeted the PR to merge into the default branch
• I have included unit tests for the issue/feature
• I have successfully run a local build

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (502094f) 84.62% compared to head (a584fdf) 84.66%.
Report is 4 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1881      +/-   ##
==========================================
+ Coverage   84.62%   84.66%   +0.04%     
==========================================
  Files         309      309              
  Lines        6818     6836      +18     
  Branches     1050     1052       +2     
==========================================
+ Hits         5770     5788      +18     
  Misses        839      839              
  Partials      209      209              

Flag	Coverage Δ
linux	84.66% <100.00%> (+0.04%)	⬆️
macos	84.66% <100.00%> (+0.04%)	⬆️
windows	?

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[pekspro]

I just want to say thank you for this. I did not expect this at all :-)

[hayohayo]

I did not investigate further, but when I update Polly.Extensions from 8.2.0 to 8.3.0 I start getting this exception:

System.InvalidOperationException: This service descriptor is keyed. Your service provider may not support keyed services.
   at Microsoft.Extensions.DependencyInjection.ServiceDescriptor.ThrowKeyedDescriptor()
   at Microsoft.Extensions.DependencyInjection.ServiceDescriptor.get_ImplementationInstance()
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteFactory.Populate()
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteFactory..ctor(ICollection`1 descriptors)
   at Microsoft.Extensions.DependencyInjection.ServiceProvider..ctor(ICollection`1 serviceDescriptors, ServiceProviderOptions options)
   at Microsoft.Extensions.DependencyInjection.ServiceCollectionContainerBuilderExtensions.BuildServiceProvider(IServiceCollection services, ServiceProviderOptions options)
   at Microsoft.Extensions.DependencyInjection.ServiceCollectionContainerBuilderExtensions.BuildServiceProvider(IServiceCollection services)
   ...

I think it might be caused by this PR. I should mention, this application is still using .NET 6. In .NET 8 I don't see this exception.

The way I use the resilience pipeline is something like:

// On launch
services.AddResiliencePipeline<string, SomeResult>("someKey", (builder, context) => { /* ... */ });

// Inject into a singleton
class MySingleton
{
    public MySingleton(ResiliencePipelineProvider<string> resiliencePipelineProvider) { }
}

[CSharpFiasco]

I did not investigate further, but when I update Polly.Extensions from 8.2.0 to 8.3.0 I start getting this exception:

System.InvalidOperationException: This service descriptor is keyed. Your service provider may not support keyed services.
   at Microsoft.Extensions.DependencyInjection.ServiceDescriptor.ThrowKeyedDescriptor()
   at Microsoft.Extensions.DependencyInjection.ServiceDescriptor.get_ImplementationInstance()
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteFactory.Populate()
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteFactory..ctor(ICollection`1 descriptors)
   at Microsoft.Extensions.DependencyInjection.ServiceProvider..ctor(ICollection`1 serviceDescriptors, ServiceProviderOptions options)
   at Microsoft.Extensions.DependencyInjection.ServiceCollectionContainerBuilderExtensions.BuildServiceProvider(IServiceCollection services, ServiceProviderOptions options)
   at Microsoft.Extensions.DependencyInjection.ServiceCollectionContainerBuilderExtensions.BuildServiceProvider(IServiceCollection services)
   ...

I think it might be caused by this PR. I should mention, this application is still using .NET 6. In .NET 8 I don't see this exception.

The way I use the resilience pipeline is something like:

// On launch
services.AddResiliencePipeline<string, SomeResult>("someKey", (builder, context) => { /* ... */ });

// Inject into a singleton
class MySingleton
{
    public MySingleton(ResiliencePipelineProvider<string> resiliencePipelineProvider) { }
}

I believe this is related dotnet/runtime#95789