Cannot inspect parameter attributes in API Explorer with Minimal Actions #36438
Description
Describe the bug
Attributes of parameters of Minimal Actions cannot be inspected in API Explorer as the ParameterDescriptor property of the ApiParameterDescription for the parameter is always null. Further, if it were not null, the type of the value of the property would need to implement IParameterInfoParameterDescriptor so that the relevant ParameterInfo value could be accessible for inspection.
To Reproduce
The following unit test demonstrates the issue, it fails due to nameParam.ParameterDescription being null.
[Fact]
public void TestParameterAttributesCanBeInspected()
{
var apiDescription = GetApiDescription(([Description("The name.")] string name) => { });
Assert.Equal(1, apiDescription.ParameterDescriptions.Count);
var nameParam = apiDescription.ParameterDescriptions[0];
Assert.Equal(typeof(string), nameParam.Type);
Assert.Equal(typeof(string), nameParam.ModelMetadata.ModelType);
Assert.Equal(BindingSource.Query, nameParam.Source);
Assert.False(nameParam.IsRequired);
Assert.NotNull(nameParam.ParameterDescriptor); // Assertion fails here
Assert.Equal("name", nameParam.ParameterDescriptor.Name);
Assert.Equal(typeof(string), nameParam.ParameterDescriptor.ParameterType);
var descriptor = Assert.IsAssignableFrom<IParameterInfoParameterDescriptor>(nameParam.ParameterDescriptor);
Assert.NotNull(descriptor.ParameterInfo);
var description = Assert.Single(descriptor.ParameterInfo.GetCustomAttributes<DescriptionAttribute>());
Assert.NotNull(description);
Assert.Equal("The name.", description.Description);
}Further technical details
Tested as of commit b33b4d4453d93be12a847a5e0c222d86edd706a0.