Editorial: refactor PerformPromiseThen to allow no capability

Fixes tc39#694.
ljharb · Mar 21, 2018 · 578f37b · 578f37b
1 parent 4c2df13
commit 578f37b
Showing 1 changed file with 9 additions and 3 deletions.
diff --git a/spec.html b/spec.html
@@ -38204,7 +38204,7 @@ <h1>AsyncGeneratorRequest Records</h1>
             </tr>
             <tr>
               <td>[[Capability]]</td>
-              <td>A PromiseCapability record</td>
+              <td>A PromiseCapability record, or *undefined*</td>
               <td>The promise capabilities associated with this request.</td>
             </tr>
             </tbody>
@@ -38739,6 +38739,9 @@ <h1>PromiseReactionJob ( _reaction_, _argument_ )</h1>
               1. Assert: _type_ is `"Reject"`.
               1. Let _handlerResult_ be ThrowCompletion(_argument_).
           1. Else, let _handlerResult_ be Call(_handler_, *undefined*, &laquo; _argument_ &raquo;).
+          1. If _promiseCapability_ is *undefined*, then
+            1. Assert: _handlerResult_ is not an abrupt completion.
+            1. Return NormalCompletion(~empty~);
           1. If _handlerResult_ is an abrupt completion, then
             1. Let _status_ be Call(_promiseCapability_.[[Reject]], *undefined*, &laquo; _handlerResult_.[[Value]] &raquo;).
           1. Else,
@@ -39095,11 +39098,14 @@ <h1>Promise.prototype.then ( _onFulfilled_, _onRejected_ )</h1>
 
         <!-- es6num="25.4.5.3.1" -->
         <emu-clause id="sec-performpromisethen" aoid="PerformPromiseThen">
-          <h1>PerformPromiseThen ( _promise_, _onFulfilled_, _onRejected_, _resultCapability_ )</h1>
+          <h1>PerformPromiseThen ( _promise_, _onFulfilled_, _onRejected_ [ , _resultCapability_ ] )</h1>
           <p>The abstract operation PerformPromiseThen performs the &ldquo;then&rdquo; operation on _promise_ using _onFulfilled_ and _onRejected_ as its settlement actions. The result is _resultCapability_'s promise.</p>
           <emu-alg>
             1. Assert: IsPromise(_promise_) is *true*.
-            1. Assert: _resultCapability_ is a PromiseCapability Record.
+            1. If _resultCapability_ is present, then
+              1. Assert: _resultCapability_ is a PromiseCapability Record.
+            1. Else,
+              1. Set _resultCapability to *undefined*.
             1. If IsCallable(_onFulfilled_) is *false*, then
               1. Set _onFulfilled_ to *undefined*.
             1. If IsCallable(_onRejected_) is *false*, then