fix(core): deduplicate ModelInfo emission in GeminiClient (#17075)

packages/core/src/core/client.test.ts

@@ -1624,7 +1624,6 @@ ${JSON.stringify(
       expect(events).toEqual([
         { type: GeminiEventType.ModelInfo, value: 'default-routed-model' },
         { type: GeminiEventType.InvalidStream },
-        { type: GeminiEventType.ModelInfo, value: 'default-routed-model' },
         { type: GeminiEventType.Content, value: 'Continued content' },
       ]);
 
@@ -1712,13 +1711,13 @@ ${JSON.stringify(
       const events = await fromAsync(stream);
 
       // Assert
-      // We expect 4 events (model_info + original + model_info + 1 retry)
+      // We expect 3 events (model_info + original + 1 retry)
-      expect(events.length).toBe(4);
+      expect(events.length).toBe(3);
       expect(
         events
-          .filter((e) => e.type !== GeminiEventType.ModelInfo)
+          .filter((e) => e.type === GeminiEventType.ModelInfo)
-          .every((e) => e.type === GeminiEventType.InvalidStream),
+          .map((e) => e.value),
-      ).toBe(true);
+      ).toEqual(['default-routed-model']);
 
       // Verify that turn.run was called twice
       expect(mockTurnRunFn).toHaveBeenCalledTimes(2);

packages/core/src/core/client.ts

@@ -628,9 +628,10 @@ export class GeminiClient {
     );
     modelToUse = finalModel;
 
-    this.currentSequenceModel = modelToUse;
+    if (!signal.aborted && !this.currentSequenceModel) {
       yield { type: GeminiEventType.ModelInfo, value: modelToUse };
-
+    }
+    this.currentSequenceModel = modelToUse;
     const resultStream = turn.run(modelConfigKey, request, linkedSignal);
     let isError = false;
     let isInvalidStream = false;