Fix issue #6098: Prevent duplicate error message display in chat interface (#7858)

frontend/__tests__/services/observations.test.ts

@@ -0,0 +1,51 @@
+import { beforeEach, describe, expect, it, vi } from "vitest";
+import { handleObservationMessage } from "#/services/observations";
+import store from "#/store";
+import { ObservationMessage } from "#/types/message";
+
+// Mock dependencies
+vi.mock("#/store", () => ({
+  default: {
+    dispatch: vi.fn(),
+  },
+}));
+
+describe("Observations Service", () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+  });
+
+  describe("handleObservationMessage", () => {
+    const createErrorMessage = (): ObservationMessage => ({
+      id: 14,
+      timestamp: "2025-04-14T13:37:54.451843",
+      message: "The action has not been executed.",
+      cause: 12,
+      observation: "error",
+      content: "The action has not been executed.",
+      extras: {
+        error_id: "",
+        metadata: {},
+      },
+    });
+
+    it("should dispatch error messages exactly once", () => {
+      const errorMessage = createErrorMessage();
+
+      handleObservationMessage(errorMessage);
+
+      expect(store.dispatch).toHaveBeenCalledTimes(1);
+      expect(store.dispatch).toHaveBeenCalledWith({
+        type: "chat/addAssistantObservation",
+        payload: expect.objectContaining({
+          observation: "error",
+          content: "The action has not been executed.",
+          source: "user",
+          extras: {
+            error_id: "",
+          },
+        }),
+      });
+    });
+  });
+});

frontend/src/services/observations.ts

@@ -52,6 +52,7 @@ export function handleObservationMessage(message: ObservationMessage) {
     case ObservationType.THINK:
     case ObservationType.NULL:
     case ObservationType.RECALL:
+    case ObservationType.ERROR:
       break; // We don't display the default message for these observations
     default:
       store.dispatch(addAssistantMessage(message.message));

frontend/src/types/observation-type.tsx

@@ -32,6 +32,9 @@ enum ObservationType {
   // An observation that shows agent's context extension
   RECALL = "recall",
 
+  // An error observation
+  ERROR = "error",
+
   // A no-op observation
   NULL = "null",
 }