Async/await Promise dependency graph

src/js/promise.js

Index: src/js/promise.js
diff --git a/src/js/promise.js b/src/js/promise.js
index 32c6af15ce466f6f012df4d5eb1d6bb1fcc5bc81..aa2cdaf2fba8db1fc155c9561d1332339f081884 100644
--- a/src/js/promise.js
+++ b/src/js/promise.js
@@ -236,7 +236,7 @@ function IsPromise(x) {
 }
 
 function PromiseCreate() {
-  return new GlobalPromise(PromiseNopResolver)
+  return new GlobalPromise(PromiseNopResolver);
 }
 
 // ES#sec-promise-resolve-functions
@@ -287,6 +287,10 @@ function ResolvePromise(promise, resolution) {
       var id;
       var name = "PromiseResolveThenableJob";
       var instrumenting = DEBUG_IS_ACTIVE;
+      if (!IS_UNDEFINED(resolution) && DEBUG_IS_ACTIVE && IsPromise(resolution)) {

[gsathya, 2016/09/08 21:38:58]

nit: format, s/DEBUG_IS_ACTIVE/instrumenting, and can you make instrumenting the
first conditional on this?

[Dan Ehrenberg, 2016/09/12 22:49:25]

Done

+        // Mark the dependency of the new promise on the resolution
+        SET_PRIVATE(resolution, promiseAwaitHandlerSymbol, promise);
+      }
       %EnqueueMicrotask(function() {
         if (instrumenting) {
           %DebugAsyncTaskEvent({ type: "willHandle", id: id, name: name });
@@ -537,7 +541,10 @@ function PromiseRace(iterable) {
 // Utility for debugger
 
 function PromiseHasUserDefinedRejectHandlerCheck(handler, deferred) {
-  if (GET_PRIVATE(handler, promiseAwaitHandlerSymbol)) return false;
+  var outerPromise = GET_PRIVATE(handler, promiseAwaitHandlerSymbol);
+  if (outerPromise) {
+    return PromiseHasUserDefinedRejectHandlerRecursive(outerPromise);
+  }
   if (handler !== PromiseIdRejectHandler) {
     var combinedDeferred = GET_PRIVATE(handler, promiseCombinedDeferredSymbol);
     if (IS_UNDEFINED(combinedDeferred)) return true;
@@ -553,6 +560,10 @@ function PromiseHasUserDefinedRejectHandlerCheck(handler, deferred) {
 function PromiseHasUserDefinedRejectHandlerRecursive(promise) {
   var handledHintSymbol = GET_PRIVATE(promise, promiseHandledHintSymbol);
   if (handledHintSymbol) return true;
+  var outerPromise = GET_PRIVATE(promise, promiseAwaitHandlerSymbol);
+  if (outerPromise) {
+    return PromiseHasUserDefinedRejectHandlerRecursive(outerPromise);
+  }
   var queue = GET_PRIVATE(promise, promiseRejectReactionsSymbol);
   var deferreds = GET_PRIVATE(promise, promiseDeferredReactionsSymbol);
   if (IS_UNDEFINED(queue)) return false;