fix(sdk): platform resource api for non existent resources (datahub-p…

…roject#11610)

metadata-ingestion/src/datahub/api/entities/platformresource/platform_resource.py

@@ -186,10 +186,17 @@ def to_datahub(self, graph_client: DataHubGraph) -> None:
     def from_datahub(
         cls, graph_client: DataHubGraph, key: Union[PlatformResourceKey, str]
     ) -> Optional["PlatformResource"]:
+        """
+        Fetches a PlatformResource from the graph given a key.
+        Key can be either a PlatformResourceKey object or an urn string.
+        Returns None if the resource is not found.
+        """
         if isinstance(key, PlatformResourceKey):
             urn = PlatformResourceUrn(id=key.id)
         else:
             urn = PlatformResourceUrn.from_string(key)
+        if not graph_client.exists(str(urn)):
+            return None
         platform_resource = graph_client.get_entity_semityped(str(urn))
         return cls(
             id=urn.id,

smoke-test/tests/platform_resources/test_platform_resource.py

@@ -99,3 +99,16 @@ def test_platform_resource_search(graph_client, test_id, cleanup_resources):
     ]
     assert len(search_results) == 1
     assert search_results[0] == platform_resource
+
+
+def test_platform_resource_non_existent(graph_client, test_id):
+    key = PlatformResourceKey(
+        platform=f"test_platform_{test_id}",
+        resource_type=f"test_resource_type_{test_id}",
+        primary_key=f"test_primary_key_{test_id}",
+    )
+    platform_resource = PlatformResource.from_datahub(
+        key=key,
+        graph_client=graph_client,
+    )
+    assert platform_resource is None