enable synchronous inspection

Author: maxkorp

src/index.js

@@ -5,3 +5,4 @@ require('./done.js');
 require('./finally.js');
 require('./es6-extensions.js');
 require('./node-extensions.js');
+require('./synchronous.js');

src/synchronous.js

@@ -0,0 +1,34 @@
+'use strict';
+
+var Promise = require('./core.js');
+
+module.exports = Promise;
+Promise.enableSynchronous = function () {
+  Promise.prototype.isPending = function() {
+    return this._state == 0;
+  };
+
+  Promise.prototype.isFulfilled = function() {
+    return this._state == 1;
+  };
+
+  Promise.prototype.isRejected = function() {
+    return this._state == 2;
+  };
+
+  Promise.prototype.value = function () {
+    if (!this.isFulfilled()) {
+      throw new Error('Cannot get a value of an unfulfilled promise.');
+    }
+
+    return this._value;
+  };
+
+  Promise.prototype.reason = function () {
+    if (!this.isRejected()) {
+      throw new Error('Cannot get a rejection reason of a non-rejected promise.');
+    }
+
+    return this._value;
+  };
+};