Request Delegate Generator fails to compile endpoint with Uri? parameter with CS8600 errors

[martincostello]

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

Enabling the Request Delegate Generator for an endpoint which has a Uri? parameter fails to compile with the following errors:

C:\Coding\martincostello\alexa-london-travel-site\src\LondonTravel.Site\Microsoft.AspNetCore.Http.RequestDelegateGenerator\Microsoft.AspNetCore.Http.RequestDelegateGenerator.RequestDelegateGenerator\GeneratedRouteBuilderExtensios.g.cs(173,70): error CS8600: Converting null literal or possible null value to non-nullable type. [C:\Coding\martincostello\alexa-london-travel-site\src\LondonTravel.Site\LondonTravel.Site.csproj]
C:\Coding\martincostello\alexa-london-travel-site\src\LondonTravel.Site\Microsoft.AspNetCore.Http.RequestDelegateGenerator\Microsoft.AspNetCore.Http.RequestDelegateGenerator.RequestDelegateGenerator\GeneratedRouteBuilderExtensios.g.cs(180,55): error CS8600: Converting null literal or possible null value to non-nullable type. [C:\Coding\martincostello\alexa-london-travel-site\src\LondonTravel.Site\LondonTravel.Site.csproj]
C:\Coding\martincostello\alexa-london-travel-site\src\LondonTravel.Site\Microsoft.AspNetCore.Http.RequestDelegateGenerator\Microsoft.AspNetCore.Http.RequestDelegateGenerator.RequestDelegateGenerator\GeneratedRouteBuilderExtensios.g.cs(223,70): error CS8600: Converting null literal or possible null value to non-nullable type. [C:\Coding\martincostello\alexa-london-travel-site\src\LondonTravel.Site\LondonTravel.Site.csproj]
C:\Coding\martincostello\alexa-london-travel-site\src\LondonTravel.Site\Microsoft.AspNetCore.Http.RequestDelegateGenerator\Microsoft.AspNetCore.Http.RequestDelegateGenerator.RequestDelegateGenerator\GeneratedRouteBuilderExtensios.g.cs(230,55): error CS8600: Converting null literal or possible null value to non-nullable type. [C:\Coding\martincostello\alexa-london-travel-site\src\LondonTravel.Site\LondonTravel.Site.csproj]

It appears that the nullability of the parameter is lost in the generated code:

- global::System.Uri redirectUri_parsed_temp = default;
+ global::System.Uri? redirectUri_parsed_temp = default;
if (Uri.TryCreate(redirectUri_temp!, UriKind.RelativeOrAbsolute, out var redirectUri_temp_parsed_non_nullable))
{
    redirectUri_parsed_temp = redirectUri_temp_parsed_non_nullable;
}
else if (string.IsNullOrEmpty(redirectUri_temp))
{
    redirectUri_parsed_temp = null;
}
else
{
    wasParamCheckFailure = true;
}

Expected Behavior

The Request Delegate Generator should emit code that compiles.

Steps To Reproduce

1. Clone martincostello/alexa-london-travel-site@b340894
2. Run build.ps1

Exceptions (if any)

No response

.NET Version

8.0.100-preview.4.23260.5

Anything else?

No response

[mitchdenny]

Thanks for reporting this. Will look into it and check why our test coverage missies this.