fix: Data resources

Data resources differ, in that the link is 'data.', stripping the
'data_' from the resource name. This fixes data refs

src/cally/cdk/__init__.py

@@ -70,7 +70,7 @@ def __init__(self, tf_identifier: Optional[str] = None, **kwargs) -> None:
 
     def __str__(self) -> str:
         if self.tf_identifier:
-            return f'${{{self.resource}.{self.tf_identifier}.id}}'
+            return f'${{{self.tf_resource}.{self.tf_identifier}.id}}'
         return self.__class__.__name__
 
     def __getattr__(self, item: str) -> Optional[str]:
@@ -80,7 +80,7 @@ def __getattr__(self, item: str) -> Optional[str]:
         if item in {'attributes', 'defaults', '_instantiated_resource'}:
             return None
         if self.tf_identifier:
-            return f'${{{self.resource}.{self.tf_identifier}.{item}}}'
+            return f'${{{self.tf_resource}.{self.tf_identifier}.{item}}}'
         return None
 
     def _get_attribute_default(self, name: str) -> Any:
@@ -113,6 +113,12 @@ def _build_attributes(
     def tf_identifier(self) -> Optional[str]:
         return self._tf_identifier
 
+    @property
+    def tf_resource(self) -> Optional[str]:
+        if self.resource.startswith('data_'):
+            return f'data.{self.resource[5:]}'
+        return self.resource
+
     def construct_resource(
         self,
         scope: Optional[Construct] = None,

tests/stacks/test_resources.py

@@ -113,3 +113,14 @@ class StorageBucket(CallyResource):
                 }
             ],
         )
+
+    def test_data_resource_reference(self):
+        class DataGoogleStorageBucket(CallyResource):
+            provider = 'google'
+            resource = 'data_google_storage_bucket'
+            defaults = MappingProxyType({'location': 'AUSTRALIA-SOUTHEAST1'})
+
+        self.assertEqual(
+            str(DataGoogleStorageBucket('bucketo', name='fish')),
+            '${data.google_storage_bucket.bucketo.id}',
+        )