implemented decycle for JSON.stringify that should work in IE

lib/render.js

@@ -1,6 +1,5 @@
 var Stream = require('stream');
 var json = typeof JSON === 'object' ? JSON : require('jsonify');
-var getSerialize = require('json-stringify-safe').getSerialize()
 
 module.exports = Render;
 
@@ -71,8 +70,8 @@ function encodeResult (res, count) {
         output += outer + '---\n';
         output += inner + 'operator: ' + res.operator + '\n';
 
-        var ex = json.stringify(res.expected, getSerialize) || '';
-        var ac = json.stringify(res.actual, getSerialize) || '';
+        var ex = json.stringify(res.expected, getSerialize()) || '';
+        var ac = json.stringify(res.actual, getSerialize()) || '';
 
         if (Math.max(ex.length, ac.length) > 65) {
             output += inner + 'expected:\n' + inner + '  ' + ex + '\n';
@@ -99,3 +98,28 @@ function encodeResult (res, count) {
 
     return output;
 }
+
+function getSerialize() {
+    var seen = [];
+
+    return function (key, value) {
+        var ret = value;
+        if (typeof value === 'object' && value) {
+            var found = false
+            for (var i = 0; i < seen.length; i++) {
+                if (seen[i] === value) {
+                    found = true
+                    break;
+                }
+            }
+
+            if (found) {
+                ret = '[Circular]'
+            } else {
+                seen.push(value)
+            }
+        }
+
+        return ret
+    }
+}

package.json

@@ -11,8 +11,7 @@
     "dependencies" : {
         "jsonify" : "~0.0.0",
         "deep-equal" : "~0.0.0",
-        "defined" : "~0.0.0",
-        "json-stringify-safe": "~4.0.0"
+        "defined" : "~0.0.0"
     },
     "devDependencies" : {
         "tap" : "~0.3.0",