Configuration binding source generator doesn't handle generics correctly

[eerhardt]

When trying to use the configuration binder source generator with an expression that uses a closed-generic type, I'm getting a warning saying it isn't supported.

However, since the expression is a closed-generic type, the type is able to be understood. In this case, the type is OidcProviderOptions.

We have this case in ASP.NET Auth. Specifically the Blazor WASM project templates use this exact pattern.

https://github.com/dotnet/aspnetcore/blob/24bbfb6d8398684091cc970bd342df185c8f9421/src/ProjectTemplates/Web.ProjectTemplates/content/ComponentsWebAssembly-CSharp/Program.cs#L15C1-L21

Repro steps

dotnet build the following app.

using Microsoft.Extensions.Configuration;

var config = new ConfigurationBuilder().Build();

AddOidcAuthentication(options =>
{
    config.Bind("Local", options.ProviderOptions);  // warning HERE
});

static void AddOidcAuthentication(Action<RemoteAuthenticationOptions<OidcProviderOptions>> configure)
{
    configure(new());
}

public class RemoteAuthenticationOptions<TRemoteAuthenticationProviderOptions> where TRemoteAuthenticationProviderOptions : new()
{
    public TRemoteAuthenticationProviderOptions ProviderOptions { get; } = new TRemoteAuthenticationProviderOptions();
}

public class OidcProviderOptions
{
    public string? Authority { get; set; }
}

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

  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>net8.0</TargetFramework>
    <ImplicitUsings>enable</ImplicitUsings>
    <Nullable>enable</Nullable>
    <EnableConfigurationBindingGenerator>true</EnableConfigurationBindingGenerator>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="Microsoft.Extensions.Configuration" Version="8.0.0-preview.7.23370.3" />
    <PackageReference Include="Microsoft.Extensions.Configuration.Binder" Version="8.0.0-preview.7.23370.3" />
  </ItemGroup>

</Project>

Expected results

The above app should build successfully with no warnings or errors.

Actual results

Program.cs(7,5): warning SYSLIB1104: Binding logic was not generated for a binder call. Unsupported input patterns include generic calls and passing boxed objects.

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Issue Details

---

When trying to use the configuration binder source generator with an expression that uses a closed-generic type, I'm getting a warning saying it isn't supported.

However, since the expression is a closed-generic type, the type is able to be understood. In this case, the type is OidcProviderOptions.

We have this case in ASP.NET Auth. Specifically the Blazor WASM project templates use this exact pattern.

https://github.com/dotnet/aspnetcore/blob/24bbfb6d8398684091cc970bd342df185c8f9421/src/ProjectTemplates/Web.ProjectTemplates/content/ComponentsWebAssembly-CSharp/Program.cs#L15C1-L21

Repro steps

dotnet build the following app.

using Microsoft.Extensions.Configuration;

var config = new ConfigurationBuilder().Build();

AddOidcAuthentication(options =>
{
    config.Bind("Local", options.ProviderOptions);  // warning HERE
});

static void AddOidcAuthentication(Action<RemoteAuthenticationOptions<OidcProviderOptions>> configure)
{
    configure(new());
}

public class RemoteAuthenticationOptions<TRemoteAuthenticationProviderOptions> where TRemoteAuthenticationProviderOptions : new()
{
    public TRemoteAuthenticationProviderOptions ProviderOptions { get; } = new TRemoteAuthenticationProviderOptions();
}

public class OidcProviderOptions
{
    public string? Authority { get; set; }
}

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

  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>net8.0</TargetFramework>
    <ImplicitUsings>enable</ImplicitUsings>
    <Nullable>enable</Nullable>
    <EnableConfigurationBindingGenerator>true</EnableConfigurationBindingGenerator>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="Microsoft.Extensions.Configuration" Version="8.0.0-preview.7.23370.3" />
    <PackageReference Include="Microsoft.Extensions.Configuration.Binder" Version="8.0.0-preview.7.23370.3" />
  </ItemGroup>

</Project>

Expected results

The above app should build successfully with no warnings or errors.

Actual results

Program.cs(7,5): warning SYSLIB1104: Binding logic was not generated for a binder call. Unsupported input patterns include generic calls and passing boxed objects.

Author:	eerhardt
Assignees:	-
Labels:	area-Extensions-Configuration
Milestone:	-

[layomia]

Thanks, I'll take a look. I think I fixed something similar in e4e0810#diff-c941b7a8491ae8b0d73a97808f886062a388c3d59da08b281d56eb0c2afbc2c5R126.

[layomia]

We have this case in ASP.NET Auth. Specifically the Blazor WASM project templates use this exact pattern.

@eerhardt per our offline discussion, there's a workaround for the templates (go back to disabling the generator for now) and we don't need a fix for this in Preview 7. We'll make a fix in RC.