Trigger debug event on not yet caught exception in promises.

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

+// Copyright 2014 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: --harmony-promises --expose-debug-as debug
+
+// Test debug events when we only listen to uncaught exceptions and
+// there is a catch handler for the exception thrown in a Promise.
+// Expectation:
+//  - only the PendingExceptionInPromise debug event is triggered.
+
+Debug = debug.Debug;
+
+var log = [];
+var step = 0;
+
+var p = new Promise(function(resolve, reject) {
+  log.push("resolve");
+  resolve();
+});
+
+var q = p.chain(
+  function() {
+    log.push("throw");
+    throw new Error("uncaught");
+  });
+
+function listener(event, exec_state, event_data, data) {
+  try {
+    // Ignore exceptions during startup in stress runs.
+    if (step >= 1) return;
+    assertEquals(["resolve", "end main", "throw"], log);
+    if (event == Debug.DebugEvent.Exception) {
+      assertUnreachable();
+    } else if (event == Debug.DebugEvent.PendingExceptionInPromise) {
+      assertEquals(0, step);
+      assertEquals("uncaught", event_data.exception().message);
+      assertTrue(event_data.promise() instanceof Promise);
+      assertTrue(event_data.uncaught());
+      step++;
+    }
+  } catch (e) {
+    // Signal a failure with exit code 1.  This is necessary since the
+    // debugger swallows exceptions and we expect the chained function
+    // and this listener to be executed after the main script is finished.
+    print("Unexpected exception: " + e + "\n" + e.stack);
+    quit(1);
+  }
+}
+
+Debug.setBreakOnUncaughtException();
+Debug.setListener(listener);
+
+log.push("end main");