Change which ExceptionEvents are triggered by Promises

test/mjsunit/es6/debug-promises/promise-race-uncaught.js

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Flags: --expose-debug-as debug --allow-natives-syntax
 
 // Test debug events when we only listen to uncaught exceptions and a
 // Promise p3 created by Promise.race has no catch handler, and is rejected
-// because one of the Promises p2 passed to Promise.all is rejected. We
-// expect two Exception debug events to be triggered, for p2 and p3 each,
-// because neither has an user-defined catch handler.
+// because one of the Promises p2 passed to Promise.race is rejected.
+// We expect one event for p2; the system recognizes the rejection of p3
+// to be redundant and based on the rejection of p2 and does not trigger
+// an additional rejection.
 
 var Debug = debug.Debug;
 
-var expected_events = 2;
+var expected_events = 1;
 var log = [];
 
 var p1 = Promise.resolve();
 p1.name = "p1";
 
 var p2 = p1.then(function() {
   log.push("throw");
   throw new Error("uncaught");  // event
 });
 
 p2.name = "p2";
 
 var p3 = Promise.race([p2]);
 p3.name = "p3";
 
 function listener(event, exec_state, event_data, data) {
   if (event != Debug.DebugEvent.Exception) return;
   try {
     expected_events--;
     assertTrue(expected_events >= 0);
     assertEquals("uncaught", event_data.exception().message);
     assertTrue(event_data.promise() instanceof Promise);
-    if (expected_events === 1) {
-      // Assert that the debug event is triggered at the throw site.
-      assertTrue(exec_state.frame(0).sourceLineText().indexOf("// event") > 0);
-      assertEquals("p2", event_data.promise().name);
-    } else {
-      assertEquals("p3", event_data.promise().name);
-    }
+    // Assert that the debug event is triggered at the throw site.
+    assertTrue(exec_state.frame(0).sourceLineText().indexOf("// event") > 0);
+    assertEquals("p2", event_data.promise().name);
     assertTrue(event_data.uncaught());
   } catch (e) {
     %AbortJS(e + "\n" + e.stack);
   }
 }
 
 Debug.setBreakOnUncaughtException();
 Debug.setListener(listener);
 
 log.push("end main");
 
 function testDone(iteration) {
   function checkResult() {
     try {
       assertTrue(iteration < 10);
       if (expected_events === 0) {
         assertEquals(["end main", "throw"], log);
       } else {
         testDone(iteration + 1);
       }
     } catch (e) {
       %AbortJS(e + "\n" + e.stack);
     }
   }
 
   %EnqueueMicrotask(checkResult);
 }
 
 testDone(0);