fix: fatal hard-crash on loop detection via unhandled AbortError (#20108)

Co-authored-by: Tommaso Sciortino <sciortino@gmail.com>

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

@@ -1244,9 +1244,6 @@ ${JSON.stringify(
         count: 2,
       });
 
-      const abortSpy = vi.spyOn(AbortController.prototype, 'abort');
-
-      // Act
       const stream = client.sendMessageStream(
         [{ text: 'Hi' }],
         new AbortController().signal,
@@ -1267,7 +1264,6 @@ ${JSON.stringify(
 
       // Assert
       expect(events).toContainEqual({ type: GeminiEventType.LoopDetected });
-      expect(abortSpy).toHaveBeenCalled();
       expect(finalResult).toBeInstanceOf(Turn);
     });
 

packages/core/src/core/client.ts

@@ -684,9 +684,6 @@ export class GeminiClient {
     // Re-initialize turn with fresh history
     turn = new Turn(this.getChat(), prompt_id);
 
-    const controller = new AbortController();
-    const linkedSignal = AbortSignal.any([signal, controller.signal]);
-
     const loopResult = await this.loopDetector.turnStarted(signal);
     if (loopResult.count > 1) {
       yield { type: GeminiEventType.LoopDetected };
@@ -747,7 +744,7 @@ export class GeminiClient {
     const resultStream = turn.run(
       modelConfigKey,
       request,
-      linkedSignal,
+      signal,
       displayContent,
     );
     let isError = false;
@@ -783,7 +780,6 @@ export class GeminiClient {
     }
 
     if (loopDetectedAbort) {
-      controller.abort();
       return turn;
     }
 
@@ -795,10 +791,8 @@ export class GeminiClient {
         boundedTurns,
         isInvalidStreamRetry,
         displayContent,
-        controller,
       );
     }
-
     if (isError) {
       return turn;
     }
@@ -1252,10 +1246,7 @@ export class GeminiClient {
     boundedTurns: number,
     isInvalidStreamRetry: boolean,
     displayContent?: PartListUnion,
-    controllerToAbort?: AbortController,
   ): AsyncGenerator<ServerGeminiStreamEvent, Turn> {
-    controllerToAbort?.abort();
-
     // Clear the detection flag so the recursive turn can proceed, but the count remains 1.
     this.loopDetector.clearDetection();