GQL011: The type must not be convertible to IGraphType

Cause

This rule triggers when a type implementing IGraphType used as the type argument when the type argument must NOT be convertible to IGraphType.

Rule description

Multiple generic types and methods in the GraphQL library receive unconstrained type arguments. This diagnostic rule simulates where T : not IGraphType constraint which is not supported in .NET.

How to fix violations

Use appropriate type argument.

Example of a violation

In the following example the PersonGraphType is incorrectly used as the type argument of the InterfaceGraphType<TSource> type.

public class MyInterfaceGraphType : InterfaceGraphType<PersonGraphType>
{
}

public class PersonGraphType : ObjectGraphType<Person>
{
}

public class Person { }

In this example, the StringGraphType is incorrectly used as the return type of the resolver

public class MyGraphType : ObjectGraphType
{
    public MyGraphType()
    {
        Field<StringGraphType>("name")
            .Returns<StringGraphType>()
            .Resolve(context => null);
    }
}

Example of how to fix

Use Person as the argument type of the InterfaceGraphType<TSource> type

public class MyInterfaceGraphType : InterfaceGraphType<Person>
{
}

public class PersonGraphType : ObjectGraphType<Person>
{
}

public class Person { }

Use string type as the return type of the resolver

public class MyGraphType : ObjectGraphType
{
    public MyGraphType()
    {
        Field<StringGraphType>("name")
            .Returns<string>()
            .Resolve(context => null);
    }
}

Suppress a warning

If you just want to suppress a single violation, add preprocessor directives to your source file to disable and then re-enable the rule.

#pragma warning disable GQL011
// The code that's violating the rule is on this line.
#pragma warning restore GQL011

To disable the rule for a file, folder, or project, set its severity to none in the configuration file.

[*.cs]
dotnet_diagnostic.GQL011.severity = none

For more information, see How to suppress code analysis warnings.

Related rules