fixed merge conflicts

Author: James Halliday

index.js

@@ -5,6 +5,8 @@ module.exports = function (obj, opts) {
     if (typeof opts === 'function') opts = { cmp: opts };
     var space = opts.space || '';
     if (typeof space === 'number') space = Array(space+1).join(' ');
+    var cycles = (typeof opts.cycles === 'boolean') ? opts.cycles : false;
+    
     var cmp = opts.cmp && (function (f) {
         return function (node) {
             return function (a, b) {
@@ -15,9 +17,11 @@ module.exports = function (obj, opts) {
         };
     })(opts.cmp);
 
+    var seen = [];
     return (function stringify (node, level) {
         var indent = space ? ('\n' + new Array(level + 1).join(space)) : '';
         var colonSeparator = space ? ': ' : ':';
+        
         if (typeof node !== 'object' || node === null) {
             return json.stringify(node);
         }
@@ -30,6 +34,12 @@ module.exports = function (obj, opts) {
             return '[' + out.join(',') + indent + ']';
         }
         else {
+            if (seen.indexOf(node) !== -1) {
+                if (cycles) return stringify('__cycle__');
+                else throw new TypeError('Converting circular structure to JSON');
+            } else {
+                seen.push(node);
+            }
             var keys = objectKeys(node).sort(cmp && cmp(node));
             var out = [];
             for (var i = 0; i < keys.length; i++) {

test/nested.js

@@ -6,3 +6,23 @@ test('nested', function (t) {
     var obj = { c: 8, b: [{z:6,y:5,x:4},7], a: 3 };
     t.equal(stringify(obj), '{"a":3,"b":[{"x":4,"y":5,"z":6},7],"c":8}');
 });
+
+test('cyclic (default)', function (t) {
+    t.plan(1);
+    var one = { a: 1 };
+    var two = { a: 2, one: one };
+    one.two = two;
+    try {
+    	stringify(one);
+    } catch (ex) {
+    	t.equal(ex.toString(), 'TypeError: Converting circular structure to JSON');
+    }
+});
+
+test('cyclic (specifically allowed)', function (t) {
+    t.plan(1);
+    var one = { a: 1 };
+    var two = { a: 2, one: one };
+    one.two = two;
+    t.equal(stringify(one, {cycles:true}), '{"a":1,"two":{"a":2,"one":"__cycle__"}}');
+});