RDG does not support [FromQuery] for optional parameters

[ryanseipp]

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

The Request Delegate Generator does not properly handle optional delegate parameters annotated with [FromQuery], as it does not convert from a string to the expected type.

Removing the attribute removes the error.

In the generated code, the last line of code produces the error.

                    var test_raw = httpContext.Request.Query["test"];
                    var test_temp = test_raw.Count > 0 ? (string?)test_raw : 10;

Without the attribute, the RDG generates this code

                    var test2_raw = test2_RouteOrQueryResolver(httpContext);
                    var test2_temp = test2_raw.Count > 0 ? (string?)test2_raw : null;

In both cases, the resulting parameter appears to be properly defaulted to the value prescribed assuming the temp value is null or empty.

Expected Behavior

A parameter should be allowed to be annotated with [FromQuery] to be explicit around resolution of the parameter. The parameter should also be allowed to be optional with a default.

Steps To Reproduce

https://github.com/ryanseipp/dotnet-aot-from-query

See Program.cs line 28

Exceptions (if any)

/home/user/Code/dotnet-aot-from-query/DotnetAotFromQuery/Microsoft.AspNetCore.Http.RequestDelegateGenerator/Microsoft.AspNetCore.Http.RequestDelegateGenerator.RequestDelegateGenerator/GeneratedRouteBuilderExtensions.g.cs(209,37): error CS0173: Type of conditional expression cannot be determined because there is no implicit conversion between 'string' and 'int' [/home/user/Code/dotnet-aot-from-query/DotnetAotFromQuery/DotnetAotFromQuery.csproj]

.NET Version

8.0.100

Anything else?

No response

[captainsafia]

@ryanseipp Thanks for reporting this issue! I've opened a PR with a fix.