dotnet/runtime
View on GitHubNullabilityInfoContext returns incorrect results for an indexer parameter if the class has a property with a value type return type.
Open
#101,071 opened on Apr 15, 2024
area-System.Reflectionbughelp wanted
Repository metrics
- Stars
- (17,886 stars)
- PR merge metrics
- (Avg merge 12d 11h) (661 merged PRs in 30d)
Description
Description
If you have a class with: a) a property which returns a value tuple; and b) an indexer with a non-nullable reference type parameter
then when looking at the NullabilityInfoContext for the indexer parameter, it appears as Unknown instead of NotNull.
Reproduction Steps
Create a console app with the following code:
internal class Program
{
public class Foo
{
public string this[string name] => throw new NotImplementedException();
// *** If you comment out this property, the problem goes away ***
public (int A, int B) ValueTupleProp { get; }
}
static void Main(string[] args)
{
// Get the PropertyInfo for the indexer.
PropertyInfo propInfo = typeof(Foo).GetProperty("Item")!;
// Get the ParameterInfo for the indexer parameter (non-nullable string).
ParameterInfo paramInfo = propInfo.GetIndexParameters()[0];
var nullabilityInfo = new NullabilityInfoContext().Create(paramInfo);
Console.WriteLine($"{nullabilityInfo.ReadState}, {nullabilityInfo.WriteState}");
Console.ReadKey();
}
}
Expected behavior
The NullabilityInfoContext properties report NotNull.
Actual behavior
The NullabilityInfoContext properties report Unknown. However, if you comment out the ValueTupleProp property, then it magically works as expected.
Regression?
No response
Known Workarounds
No response
Configuration
Tried running in .NET 6.0 and .NET 8.0 on Windows 11.
Other information
No response