From e05a41ec00b4e947f8d3a41a6020c16949efd86b Mon Sep 17 00:00:00 2001
From: Loren Segal <lsegal@amazon.com>
Date: Mon, 25 Mar 2013 16:46:06 -0700
Subject: [PATCH] Propagate errors from all callbacks up to main runloop

Fixes #74
---
 lib/request.js                   |  7 +++----
 lib/sequential_executor.js       | 23 ++++++++++++++---------
 test/event_listeners.spec.coffee |  5 ++---
 3 files changed, 19 insertions(+), 16 deletions(-)

diff --git a/lib/request.js b/lib/request.js
index 2f49b39343..ce9acccebd 100644
--- a/lib/request.js
+++ b/lib/request.js
@@ -336,10 +336,10 @@ AWS.Request = inherit({
    },
 
   /**
-   * @private
+   * @api private
    */
   emitEvents: function emitEvents(eventNames, response, doneCallback) {
-    if (!doneCallback) doneCallback = function() {};
+    if (!doneCallback) doneCallback = this.unhandledErrorCallback;
     if (response.error) {
       doneCallback.call(this, response.error);
     } else if (eventNames.length === 0) {
@@ -362,8 +362,7 @@ AWS.Request = inherit({
    * @api private
    */
   emitEvent: function emitEvent(eventName, args, doneCallback) {
-    if (!doneCallback) doneCallback = function() {};
-
+    if (!doneCallback) doneCallback = this.unhandledErrorCallback;
     var response = null;
     if (AWS.util.isType(args, Array)) {
       response = args[args.length - 1];
diff --git a/lib/sequential_executor.js b/lib/sequential_executor.js
index 96cb36a324..f0e53f7691 100644
--- a/lib/sequential_executor.js
+++ b/lib/sequential_executor.js
@@ -85,15 +85,12 @@ AWS.SequentialExecutor = AWS.util.inherit({
    * @api private
    */
   emit: function emit(eventName, eventArgs, doneCallback) {
-    if (!doneCallback) doneCallback = function() {};
+    if (!doneCallback) doneCallback = this.unhandledErrorCallback;
+
     var listeners = this.listeners(eventName);
-    if (listeners.length === 0) {
-      doneCallback.call(this);
-      return false;
-    } else {
-      this.callListeners(listeners, eventArgs, doneCallback);
-      return true;
-    }
+    var count = listeners.length;
+    this.callListeners(listeners, eventArgs, doneCallback);
+    return count > 0;
   },
 
   /**
@@ -234,8 +231,16 @@ AWS.SequentialExecutor = AWS.util.inherit({
       }
     );
     return this;
-  }
+  },
 
+  /**
+   * @api private
+   */
+  unhandledErrorCallback: function unhandledErrorCallback(err) {
+    if (err) {
+        throw err;
+    }
+  }
 });
 
 /**
diff --git a/test/event_listeners.spec.coffee b/test/event_listeners.spec.coffee
index 38a21b89eb..ee3d893f9e 100644
--- a/test/event_listeners.spec.coffee
+++ b/test/event_listeners.spec.coffee
@@ -316,6 +316,5 @@ describe 'AWS.EventListeners', ->
       request = makeRequest()
       request.on 'error', ->
         throw "ERROR"
-      response = request.send()
-      expect(completeHandler).toHaveBeenCalled()
-      expect(response.error).toBe("ERROR")
+      expect(-> request.send()).toThrow('ERROR')
+      expect(completeHandler).not.toHaveBeenCalled()