fix(cli): suppress unhandled AbortError logs during request cancellation (#22621)

packages/cli/src/gemini.test.tsx

@@ -304,6 +304,25 @@ describe('gemini.tsx main function', () => {
     vi.restoreAllMocks();
   });
 
+  it('should suppress AbortError and not open debug console', async () => {
+    const debugLoggerErrorSpy = vi.spyOn(debugLogger, 'error');
+    const debugLoggerLogSpy = vi.spyOn(debugLogger, 'log');
+    const abortError = new DOMException(
+      'The operation was aborted.',
+      'AbortError',
+    );
+
+    setupUnhandledRejectionHandler();
+    process.emit('unhandledRejection', abortError, Promise.resolve());
+
+    await new Promise(process.nextTick);
+
+    expect(debugLoggerErrorSpy).not.toHaveBeenCalled();
+    expect(debugLoggerLogSpy).toHaveBeenCalledWith(
+      expect.stringContaining('Suppressed unhandled AbortError'),
+    );
+  });
+
   it('should log unhandled promise rejections and open debug console on first error', async () => {
     const processExitSpy = vi
       .spyOn(process, 'exit')

packages/cli/src/gemini.tsx

@@ -164,6 +164,14 @@ export function getNodeMemoryArgs(isDebugMode: boolean): string[] {
 export function setupUnhandledRejectionHandler() {
   let unhandledRejectionOccurred = false;
   process.on('unhandledRejection', (reason, _promise) => {
+    // AbortError is expected when the user cancels a request (e.g. pressing ESC).
+    // It may surface as an unhandled rejection due to async timing in the
+    // streaming pipeline, but it is not a bug.
+    if (reason instanceof Error && reason.name === 'AbortError') {
+      debugLogger.log(`Suppressed unhandled AbortError: ${reason.message}`);
+      return;
+    }
+
     const errorMessage = `=========================================
 This is an unexpected error. Please file a bug report using the /bug tool.
 CRITICAL: Unhandled Promise Rejection!