Invalid Argument Type Error

Description

This error is thrown when an argument is of the wrong type, it usually happens when passing unions or interfaces as an argument, for example the following code will throw this error:

import strawberry


@strawberry.type
class TypeA:
    id: strawberry.ID


Example = strawberry.union(name="Example", types=(TypeA,))


@strawberry.type
class Query:
    @strawberry.field
    def example(self, data: Example) -> str:
        return "this is an example"


schema = strawberry.Schema(query=Query)

Using union types as arguments

The latest GraphQL specification doesn’t allow using unions as arguments. There’s currently an RFC for adding a oneOf directive that might work for your use case, but it’s not yet implemented in the spec and Strawberry