refactor(api-core): update get_universe_domain to accept multiple potential universes

Author: hebaalazzeh

packages/google-api-core/google/api_core/gapic_v1/client_utils.py

@@ -109,13 +109,13 @@ def get_api_endpoint(
 
 
 def get_universe_domain(
-    universe_domain: Optional[str],
+    *potential_universes: Optional[str],
     default_universe: str = "googleapis.com",
 ) -> str:
     """Return the universe domain used by the client.
 
     Args:
-        universe_domain (Optional[str]): The configured universe domain.
+        *potential_universes (Optional[str]): Potential universe domains in order of preference.
         default_universe (str): The default universe domain.
 
     Returns:
@@ -124,8 +124,9 @@ def get_universe_domain(
     Raises:
         ValueError: If the resolved universe domain is an empty string.
     """
-    resolved = (
-        universe_domain.strip() if universe_domain is not None else default_universe
+    resolved = next(
+        (x.strip() for x in potential_universes if x is not None),
+        default_universe,
     )
 
     if not resolved:

packages/google-api-core/tests/unit/gapic/test_client_utils.py

@@ -164,17 +164,36 @@ def test_get_api_endpoint(
 
 def test_get_universe_domain():
     # When universe_domain is provided
-    assert get_universe_domain("foo.com", "default.com") == "foo.com"
-    assert get_universe_domain("  foo.com  ", "default.com") == "foo.com"
+    assert get_universe_domain("foo.com", default_universe="default.com") == "foo.com"
+    assert (
+        get_universe_domain("  foo.com  ", default_universe="default.com") == "foo.com"
+    )
 
     # When universe_domain is None, falls back to default_universe
-    assert get_universe_domain(None, "default.com") == "default.com"
+    assert get_universe_domain(None, default_universe="default.com") == "default.com"
+
+    # When multiple potential universes are provided, resolves in order of preference
+    assert (
+        get_universe_domain("foo.com", "bar.com", default_universe="default.com")
+        == "foo.com"
+    )
+    assert (
+        get_universe_domain(None, "bar.com", default_universe="default.com")
+        == "bar.com"
+    )
+    assert (
+        get_universe_domain(None, None, default_universe="default.com") == "default.com"
+    )
 
     # ValueError raised when resolved value is empty string
     with pytest.raises(ValueError) as excinfo:
-        get_universe_domain("", "default.com")
+        get_universe_domain("", default_universe="default.com")
+    assert str(excinfo.value) == "Universe Domain cannot be an empty string."
+
+    with pytest.raises(ValueError) as excinfo:
+        get_universe_domain("   ", default_universe="default.com")
     assert str(excinfo.value) == "Universe Domain cannot be an empty string."
 
     with pytest.raises(ValueError) as excinfo:
-        get_universe_domain("   ", "default.com")
+        get_universe_domain(None, "", default_universe="default.com")
     assert str(excinfo.value) == "Universe Domain cannot be an empty string."