1 files changed, 11 insertions, 5 deletions
diff --git a/ui/src/controller/consumer_port_types.ts b/ui/src/controller/consumer_port_types.ts
index cb054e1ba..8b3cd453c 100644
--- a/ui/src/controller/consumer_port_types.ts
+++ b/ui/src/controller/consumer_port_types.ts
@@ -18,6 +18,17 @@ export interface Typed {
   type: string;
 }
 
+// A type guard that can be used in order to be able to access the property of
+// an object in a checked manner.
+export function hasProperty<T extends object, P extends string>(
+    obj: T, prop: P): obj is T&{[prop in P]: unknown} {
+  return obj.hasOwnProperty(prop);
+}
+
+export function isTyped(obj: object): obj is Typed {
+  return obj.hasOwnProperty('type');
+}
+
 export interface ReadBuffersResponse extends
     Typed, perfetto.protos.IReadBuffersResponse {}
 export interface EnableTracingResponse extends
@@ -48,11 +59,6 @@ export function isGetTraceStatsResponse(obj: Typed):
   return obj.type === 'GetTraceStatsResponse';
 }
 
-export function isGetCategoriesResponse(obj: Typed):
-    obj is GetCategoriesResponse {
-  return obj.type === 'GetCategoriesResponse';
-}
-
 export function isFreeBuffersResponse(obj: Typed): obj is FreeBuffersResponse {
   return obj.type === 'FreeBuffersResponse';
 }