Expose promise status through promise mirror.

src/mirror-debugger.js

Index: src/mirror-debugger.js
diff --git a/src/mirror-debugger.js b/src/mirror-debugger.js
index d413b090b71a86e587329a410ae7bce46c2ae730..17bd1456abc9942dd01ad13cc658620a336884bb 100644
--- a/src/mirror-debugger.js
+++ b/src/mirror-debugger.js
@@ -42,6 +42,18 @@ function ClearMirrorCache() {
 }
 
 
+// Wrapper to check whether an object is a Promise.  The call may not work
+// if promises are not enabled.
+// TODO(yangguo): remove this wrapper once promises are enabled by default.
+function ObjectIsPromise(value) {
+  try {
+    return %IsPromise(value);
+  } catch (e) {
+    return false;
+  }
+}
+
+
 /**
  * Returns the mirror for a specified value or object.
  *
@@ -90,6 +102,8 @@ function MakeMirror(value, opt_transient) {
     mirror = new ErrorMirror(value);
   } else if (IS_SCRIPT(value)) {
     mirror = new ScriptMirror(value);
+  } else if (ObjectIsPromise(value)) {
+    mirror = new PromiseMirror(value);
   } else {
     mirror = new ObjectMirror(value, OBJECT_TYPE, opt_transient);
   }
@@ -159,6 +173,7 @@ var FRAME_TYPE = 'frame';
 var SCRIPT_TYPE = 'script';
 var CONTEXT_TYPE = 'context';
 var SCOPE_TYPE = 'scope';
+var PROMISE_TYPE = 'promise';
 
 // Maximum length when sending strings through the JSON protocol.
 var kMaxProtocolStringLength = 80;
@@ -212,6 +227,7 @@ var ScopeType = { Global: 0,
 //         - DateMirror
 //         - RegExpMirror
 //         - ErrorMirror
+//         - PromiseMirror
 //     - PropertyMirror
 //     - InternalPropertyMirror
 //     - FrameMirror
@@ -351,6 +367,15 @@ Mirror.prototype.isError = function() {
 
 
 /**
+ * Check whether the mirror reflects a promise.
+ * @returns {boolean} True if the mirror reflects a promise
+ */
+Mirror.prototype.isPromise = function() {
+  return this instanceof PromiseMirror;
+};
+
+
+/**
  * Check whether the mirror reflects a property.
  * @returns {boolean} True if the mirror reflects a property
  */
@@ -637,9 +662,9 @@ ObjectMirror.prototype.propertyNames = function(kind, limit) {
 
   // Find all the named properties.
   if (kind & PropertyKind.Named) {
-    // Get all the local property names.
+    // Get all the local property names except for private symbols.
     propertyNames =
-        %GetLocalPropertyNames(this.value_, PROPERTY_ATTRIBUTES_NONE);
+        %GetLocalPropertyNames(this.value_, PROPERTY_ATTRIBUTES_PRIVATE_SYMBOL);
     total += propertyNames.length;
 
     // Get names for named interceptor properties if any.
@@ -1172,6 +1197,33 @@ ErrorMirror.prototype.toText = function() {
 
 
 /**
+ * Mirror object for a Promise object.
+ * @param {Object} data The Promise object
+ * @constructor
+ * @extends Mirror
+ */
+function PromiseMirror(value) {
+  %_CallFunction(this, value, PROMISE_TYPE, ObjectMirror);
+}
+inherits(PromiseMirror, ObjectMirror);
+
+
+PromiseMirror.prototype.promise = function() {
+  return this.promise_;

[aandrey, 2014/04/25 13:38:25]

did you mean this.value_ ?

[Yang, 2014/04/25 13:42:51]

Nice catch. I removed this so that .value() returns the value, like is the case
for other mirror types as well. And I added a check in the test case.

+};
+
+
+PromiseMirror.Pending = 0;

[rossberg, 2014/04/25 13:29:45]

Instead of defining these constants, the status function should convert the
internal ints into descriptive strings.

[Yang, 2014/04/25 13:42:51]

Done.

+PromiseMirror.Rejected = -1;
+PromiseMirror.Resolved = +1;
+
+
+PromiseMirror.prototype.status = function() {
+  return %GetPromiseStatus(this.value_);
+};
+
+
+/**
  * Base mirror object for properties.
  * @param {ObjectMirror} mirror The mirror object having this property
  * @param {string} name The name of the property
@@ -2350,6 +2402,7 @@ JSONProtocolSerializer.prototype.serialize_ = function(mirror, reference,
     case FUNCTION_TYPE:
     case ERROR_TYPE:
     case REGEXP_TYPE:
+    case PROMISE_TYPE:
       // Add object representation.
       this.serializeObject_(mirror, content, details);
       break;
@@ -2452,7 +2505,6 @@ JSONProtocolSerializer.prototype.serializeObject_ = function(mirror, content,
     content.indexedInterceptor = true;
   }
 
-  // Add function specific properties.
   if (mirror.isFunction()) {
     // Add function specific properties.
     content.name = mirror.name();
@@ -2480,12 +2532,16 @@ JSONProtocolSerializer.prototype.serializeObject_ = function(mirror, content,
     }
   }
 
-  // Add date specific properties.
   if (mirror.isDate()) {
     // Add date specific properties.
     content.value = mirror.value();
   }
 
+  if (mirror.isPromise()) {
+    // Add promise specific properties.
+    content.status = mirror.status();
+  }
+
   // Add actual properties - named properties followed by indexed properties.
   var propertyNames = mirror.propertyNames(PropertyKind.Named);
   var propertyIndexes = mirror.propertyNames(PropertyKind.Indexed);