Update Resource.merge to return an empty resource when an error occurs

opentelemetry-sdk/src/opentelemetry/sdk/resources/__init__.py

@@ -197,9 +197,10 @@ def merge(self, other: "Resource") -> "Resource":
         If a key exists on both the old and updating resource, the value of the
         updating resource will override the old resource value.
 
-        The new `schema_url` will take an updated value only if the original
+        The updating resource's `schema_url` will be used only if the old
         `schema_url` is empty. Attempting to merge two resources with
-        different, non-empty values for `schema_url` will result in an error.
+        different, non-empty values for `schema_url` will result in an error
+        and return an empty resource.
 
         Args:
             other: The other resource to be merged.
@@ -217,10 +218,10 @@ def merge(self, other: "Resource") -> "Resource":
         elif self.schema_url == other.schema_url:
             schema_url = other.schema_url
         else:
-            schema_url = ""
             logger.error(
                 "Failed to merge resources: The Schema URL of the old and updating resources are not empty and are different"
             )
+            return _EMPTY_RESOURCE
 
         return Resource(merged_attributes, schema_url)
 

opentelemetry-sdk/tests/resources/test_resources.py

@@ -147,7 +147,7 @@ def test_resource_merge(self):
         left = resources.Resource.create({}, schema_urls[0])
         right = resources.Resource.create({}, schema_urls[1])
         with self.assertLogs(level=ERROR):
-            self.assertEqual(left.merge(right).schema_url, "")
+            self.assertEqual(left.merge(right), resources._EMPTY_RESOURCE)
 
     def test_resource_merge_empty_string(self):
         """Verify Resource.merge behavior with the empty string.