When registering instantiated extensions, the execution context field on the extension is set and hence when there are multiple requests in-flight (e.g. when using async) this can resulting in inconsistent results - e.g. errors not being masked when using the MaskErrorExtension

Describe the Bug

When registering the masked error extension via

schema = strawberry.Schema(
    Query,
    extensions=[
        MaskErrors(),
    ],
)

If there are multiple requests in flight, then some errors are not masked. This seems to be because Strawberry edits the execution context on the shared extension, meaning that the error masking logic may operate on the wrong execution context (e.g. one that has not completed).

--SchemaExtensionRunner

        for extension in extensions:
            # If the extension has already been instantiated then set the
            # `execution_context` attribute
            if isinstance(extension, SchemaExtension):
                extension.execution_context = execution_context <---here
                init_extensions.append(extension)
            else:
                init_extensions.append(extension(execution_context=execution_context))

This could be fixed by cloning the extension for each request - or by following the field extension pattern of passing the context as a method parameter

System Information

• Operating system: Mac OSX 12.6.8
• Strawberry version (if applicable): 0.204.0