Add test cases for ObjectStoragePath relative_to/is_relative_to metho…

…ds (apache#37770)

tests/io/test_path.py

@@ -17,6 +17,7 @@
 # under the License.
 from __future__ import annotations
 
+import sys
 import uuid
 from stat import S_ISDIR, S_ISREG
 from tempfile import NamedTemporaryFile
@@ -200,6 +201,26 @@ def test_replace(self):
 
         e.unlink()
 
+    @pytest.mark.skipif(sys.version_info < (3, 9), reason="`is_relative_to` new in version 3.9")
+    def test_is_relative_to(self):
+        uuid_dir = f"/tmp/{str(uuid.uuid4())}"
+        o1 = ObjectStoragePath(f"file://{uuid_dir}/aaa")
+        o2 = ObjectStoragePath(f"file://{uuid_dir}")
+        o3 = ObjectStoragePath(f"file://{str(uuid.uuid4())}")
+        assert o1.is_relative_to(o2)
+        assert not o1.is_relative_to(o3)
+
+    def test_relative_to(self):
+        uuid_dir = f"/tmp/{str(uuid.uuid4())}"
+        o1 = ObjectStoragePath(f"file://{uuid_dir}/aaa")
+        o2 = ObjectStoragePath(f"file://{uuid_dir}")
+        o3 = ObjectStoragePath(f"file://{str(uuid.uuid4())}")
+
+        _ = o1.relative_to(o2)  # Should not raise any error
+
+        with pytest.raises(ValueError):
+            o1.relative_to(o3)
+
     def test_move_local(self):
         _from = ObjectStoragePath(f"file:///tmp/{str(uuid.uuid4())}")
         _to = ObjectStoragePath(f"file:///tmp/{str(uuid.uuid4())}")