[fixlib][feat] Allow marking resource classes as not exportable

fixlib/fixlib/baseresources.py

@@ -296,6 +296,8 @@ class BaseResource(ABC):
     _categories: ClassVar[List[Category]] = []
     # Link to the cloud providers product documentation of this resource kind.
     _docs_url: ClassVar[Optional[str]] = None
+    # Mark this class as exportable. Use False for internal model classes without instances.
+    _model_export: ClassVar[bool] = True
 
     ################################################################################
     # Instance Variables

fixlib/fixlib/core/model_export.py

@@ -69,14 +69,16 @@ def transitive_classes(classes: Set[type], walk_subclasses: bool = True) -> Set[
     def check(to_check: type) -> None:
         clazz = optional_origin(to_check)
         if clazz in all_classes:
-            pass
+            return
         elif is_dict(clazz):
             key_type, value_type = dict_types(to_check)
             check(key_type)
             check(value_type)
         elif is_collection(clazz):
             check(type_arg(to_check))
         elif attrs.has(clazz):
+            if getattr(clazz, "_model_export", True) is False:
+                return
             resolve_types(clazz)
             all_classes.add(clazz)
             for mro_clazz in clazz.mro()[1:]:

fixlib/test/core/model_export_test.py

@@ -70,6 +70,13 @@ class DataClassOther(DataClassBase):
     something: str
 
 
+@define(slots=False)
+class DataClassNotExported(DataClassBase):
+    _model_export: ClassVar[bool] = False
+    kind: ClassVar[str] = "other"
+    something: str
+
+
 def test_collection() -> None:
     assert is_collection(Optional[List[str]]) is True
     assert is_collection(List[str]) is True