related false when objects do not exist

graph.dat

@@ -1,10 +1,12 @@
-[user:bob]
+[test:hello]
 
 [doc:foo]
-read = [doc:foo#owner, user:bob]
 owner = [user:alice]
-
-[user:oscar]
+read = [user:bob, doc:foo#owner]
 
 [user:alice]
 
+[user:bob]
+
+[user:oscar]
+

graph.dat.bak

@@ -1,10 +1,12 @@
-[user:bob]
+[test:hello]
 
 [doc:foo]
-read = [user:bob, doc:foo#owner]
+read = [doc:foo#owner, user:bob]
 owner = [user:alice]
 
-[user:oscar]
-
 [user:alice]
 
+[user:bob]
+
+[user:oscar]
+

src/grpc_service.rs

@@ -126,9 +126,11 @@ impl QueryService for GraphService {
     ) -> Result<Response<IsRelatedToResponse>, Status> {
         let graph = self.graph.lock().await;
 
-        let (src, dst) = transform_relation(request.get_ref(), &graph)?;
-
-        let related = graph.is_related_to(src, dst);
+        let related = if let Ok((src, dst)) = transform_relation(request.get_ref(), &graph) {
+            graph.is_related_to(src, dst)
+        } else {
+            false
+        };
 
         Ok(Response::new(IsRelatedToResponse { related }))
     }