trodrigues · December 5, 2014 13:45 · Dec 5, 2014
diff --git a/gistfile1.js b/gistfile1.js
@@ -0,0 +1,36 @@
+// use with https://www.npmjs.org/package/deep-diff
+
+toEqualObj: function () {
+  var KINDS = {
+    'N': 'newly added property/element',
+    'D': 'property/element was deleted',
+    'E': 'property/element was edited',
+    'A': 'change occurred within an array'
+  };
+
+  function formatDiff(objdiff) {
+    return objdiff.map(function (diff) {
+      return '\t'+diff.kind +' at '+ diff.path.join('.') +'\n'+
+             '\t'+diff.actual +' should be '+ diff.expected;
+    }).join('\n\n');
+  }
+
+  return {
+    compare: function (actual, expected) {
+      var objdiff = (deepDiff(expected, actual) || []).map(function (diff) {
+        return {
+          kind: KINDS[diff.kind],
+          path: diff.path,
+          expected: diff.lhs,
+          actual: diff.rhs
+        };
+      });
+
+      return {
+        pass    : objdiff.length === 0,
+        message : 'Expected object not to have differences\n\n' + formatDiff(objdiff)
+      };
+
+    }
+  };
+}