chore: add experimental blob url tests (#1463)

* chore: add experimental blob url tests

* fix

Author: GarrettWu

tests/system/small/blob/test_urls.py

@@ -0,0 +1,32 @@
+# Copyright 2025 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import bigframes
+import bigframes.pandas as bpd
+
+
+def test_blob_read_url(images_mm_df: bpd.DataFrame):
+    bigframes.options.experiments.blob = True
+
+    urls = images_mm_df["blob_col"].blob.read_url()
+
+    assert urls.str.startswith("https://storage.googleapis.com/").all()
+
+
+def test_blob_write_url(images_mm_df: bpd.DataFrame):
+    bigframes.options.experiments.blob = True
+
+    urls = images_mm_df["blob_col"].blob.write_url()
+
+    assert urls.str.startswith("https://storage.googleapis.com/").all()