Read internal properties [[PromiseStatus]] and [[PromiseValue]] of the promise.

test/mjsunit/es6/mirror-promises.js

Index: test/mjsunit/es6/mirror-promises.js
diff --git a/test/mjsunit/es6/mirror-promises.js b/test/mjsunit/es6/mirror-promises.js
index 5a21a6b9e621487b56745829ad03fbac1b16845f..a3e4a0d18e4152ccaefbd319f3a19e6c087687b4 100644
--- a/test/mjsunit/es6/mirror-promises.js
+++ b/test/mjsunit/es6/mirror-promises.js
@@ -67,3 +67,23 @@ var thrownv = new Promise(function(resolve, reject) { throw 'throw' });
 testPromiseMirror(resolvedv, "resolved", 'resolve');
 testPromiseMirror(rejectedv, "rejected", 'reject');
 testPromiseMirror(thrownv, "rejected", 'throw');
+
+// Test internal properties of different promises.
+var m1 = debug.MakeMirror(new Promise(
+    function(resolve, reject) { resolve(1) }));
+var ip = m1.internalProperties();
+assertEquals(2, ip.length);
+assertEquals("[[PromiseStatus]]", ip[0].name());
+assertEquals("[[PromiseValue]]", ip[1].name());
+assertEquals("resolved", ip[0].value().value());
+assertEquals(1, ip[1].value().value());
+
+var m2 = debug.MakeMirror(new Promise(function(resolve, reject) { reject(2) }));
+ip = m2.internalProperties();
+assertEquals("rejected", ip[0].value().value());
+assertEquals(2, ip[1].value().value());
+
+var m3 = debug.MakeMirror(new Promise(function(resolve, reject) { }));
+ip = m3.internalProperties();
+assertEquals("pending", ip[0].value().value());
+assertEquals("undefined", typeof(ip[1].value().value()));