Add more tests for imports

Author: gkevinzheng

tests/unit/admin_overlay/test_admin_packaging.py

@@ -28,12 +28,13 @@
     ],
 )
 def test_admin_overlay_object_imports(module):
-    # Simulate from <module> import <class> dynamically using importlib
+    # Simulate from <top level admin package> import <class> dynamically using importlib
     mod = importlib.import_module(module)
 
     # Check that the import aliasing works as expected for overlay/autogenerated clients/types.
     classes_to_modules = {
         "BigtableTableAdminClient": "google.cloud.bigtable.admin.overlay.services.bigtable_table_admin.client",
+        "BigtableInstanceAdminClient": "google.cloud.bigtable.admin.services.bigtable_instance_admin.client",
         "RestoreTableOperation": "google.cloud.bigtable.admin.overlay.types.restore_table",
         "BigtableInstanceAdminClient": "google.cloud.bigtable.admin.services.bigtable_instance_admin.client",
         "RestoreTableRequest": "google.cloud.bigtable.admin.types.bigtable_table_admin",
@@ -69,9 +70,16 @@ def test_admin_overlay_object_imports(module):
         ),
     ],
 )
-def test_admin_shim_import_aliasing(alias, actual):
+def test_admin_shim_import_aliasing_subpackages(alias, actual):
+    # Simulates "import <alias>" dynamically using importlib
     assert importlib.import_module(alias) == importlib.import_module(actual)
 
+    # Simulates "from google.cloud.bigtable_admin_v2.<subpackage> import <module>"
+    package, module = alias.rsplit(".", 1)
+    assert importlib.import_module(
+        f".{module}", package=package
+    ) == importlib.import_module(actual)
+
 
 @pytest.mark.parametrize(
     "alias,cls_name,subpackage_location",
@@ -104,7 +112,8 @@ def test_admin_shim_services_types_subpackage_aliasing(
     # Because of existing aliasing on the types/service subpackages in google.cloud.bigtable.admin_v2,
     # we need to see if this works with google.cloud.bigtable_admin_v2.
 
-    # Simulate from <module> import <class> dynamically using importlib
+    # Simulate both from google.cloud.bigtable_admin_v2.<subpackage> import <class>
+    # and import google.cloud.bigtable_admin_v2.<subpackage> dynamically using importlib
     alias_mod = importlib.import_module(alias)
     cls = getattr(alias_mod, cls_name)
     subpackage = importlib.import_module(subpackage_location)