1 files changed, 41 insertions, 0 deletions
diff --git a/test/sql/test_utils.py b/test/sql/test_utils.py
index 4e713dd28..d68a74475 100644
--- a/test/sql/test_utils.py
+++ b/test/sql/test_utils.py
@@ -4,8 +4,11 @@ from sqlalchemy import MetaData
 from sqlalchemy import select
 from sqlalchemy import String
 from sqlalchemy import Table
+from sqlalchemy.sql import base as sql_base
 from sqlalchemy.sql import util as sql_util
 from sqlalchemy.sql.elements import ColumnElement
+from sqlalchemy.testing import assert_raises
+from sqlalchemy.testing import assert_raises_message
 from sqlalchemy.testing import eq_
 from sqlalchemy.testing import fixtures
 
@@ -48,3 +51,41 @@ class MiscTest(fixtures.TestBase):
             set(sql_util.find_tables(subset_select, include_aliases=True)),
             {common, calias, subset_select},
         )
+
+    def test_options_merge(self):
+        class opt1(sql_base.CacheableOptions):
+            _cache_key_traversal = []
+
+        class opt2(sql_base.CacheableOptions):
+            _cache_key_traversal = []
+
+            foo = "bar"
+
+        class opt3(sql_base.CacheableOptions):
+            _cache_key_traversal = []
+
+            foo = "bar"
+            bat = "hi"
+
+        o2 = opt2.safe_merge(opt1)
+        eq_(o2.__dict__, {})
+        eq_(o2.foo, "bar")
+
+        assert_raises_message(
+            TypeError,
+            r"other element .*opt2.* is not empty, is not of type .*opt1.*, "
+            r"and contains attributes not covered here .*'foo'.*",
+            opt1.safe_merge,
+            opt2,
+        )
+
+        o2 = opt2 + {"foo": "bat"}
+        o3 = opt2.safe_merge(o2)
+
+        eq_(o3.foo, "bat")
+
+        o4 = opt3.safe_merge(o2)
+        eq_(o4.foo, "bat")
+        eq_(o4.bat, "hi")
+
+        assert_raises(TypeError, opt2.safe_merge, o4)