Make import_message_from_namespaced_type operate on NamespacedType

[mikaelarguedas]

Fixes #70

Instead of changing the type specification, which would either require changing the function name (breaking API) or have the name and the behavior mismatch (current state), this modifies the function to operate on NamespacedType instead.
This will change behavior for consumers of the function.
If this is not desired, the less disruptive alternative is to change the function specification without changing the function name or the behavior.

Added a simple test to cover the uses of the function used in this package.

[dirk-thomas]

For backward compatibility it would be nice to keep the previous usage pattern working.

We don't want to add a new function with a different name (the current name is just "right"). So how about the function checks if the passed message_type argument isn't of type NamespacedType and if that is the case and the variable has a value_type attribute then do message_type = message_type.value_type?

[mikaelarguedas]

So how about the function checks if the passed message_type argument isn't of type NamespacedType and if that is the case and the variable has a value_type attribute then do message_type = message_type.value_type?

I thought about this originally, the uncertainty I had was: "what would be the type of the argument in the signature?"

• Keep just NamespacedType even if the function can work with other types
• Use a specification matching more closely the accepted types: e.g. Union[NamespacedType, AbstractNestedType] in this case the change could simply be (though less permissive than accepting any type that has a attribute value_type):

-def import_message_from_namespaced_type(message_type: NamespacedType) -> Any:
+def import_message_from_namespaced_type(
+        message_type: Union[NamespacedType, AbstractNestedType]) -> Any:
+    if isinstance(message_type, AbstractNestedType):
+        message_type = message_type.value_type

• Something else?

[dirk-thomas]

I would choose:

Keep just NamespacedType even if the function can work with other types

I would consider the special case to keep current usage working as deprecated. Maybe add a deprecation in the case where accessing value_type so that existing usage can be updated and the logic removed in the future.

[mikaelarguedas]

Sounds good, done in 0002388

[dirk-thomas]

Please rebase against the latest state on the target branch in order to run CI.

[dirk-thomas]

Thanks for the patch:

I updated your description to automatically close the referenced issue.