Support array replacer (fixes moll#14)

Author: Marsup

stringify.js

@@ -6,7 +6,7 @@ function stringify(obj, replacer, spaces, cycleReplacer) {
 }
 
 function serializer(replacer, cycleReplacer) {
-  var stack = [], keys = []
+  var stack = [], keys = [], replacerArray = Array.isArray(replacer)
 
   if (cycleReplacer == null) cycleReplacer = function(key, value) {
     if (stack[0] === value) return "[Circular ~]"
@@ -15,13 +15,17 @@ function serializer(replacer, cycleReplacer) {
 
   return function(key, value) {
     if (stack.length > 0) {
+      if (replacerArray && replacer.indexOf(key) === -1) {
+        return
+      }
+
       var thisPos = stack.indexOf(this)
       ~thisPos ? stack.splice(thisPos + 1) : stack.push(this)
       ~thisPos ? keys.splice(thisPos, Infinity, key) : keys.push(key)
       if (~stack.indexOf(value)) value = cycleReplacer.call(this, key, value)
     }
     else stack.push(value)
 
-    return replacer == null ? value : replacer.call(this, key, value)
+    return replacer == null || replacerArray ? value : replacer.call(this, key, value)
   }
 }

test/stringify_test.js

@@ -156,6 +156,39 @@ describe("Stringify", function() {
     replacer.args[2][1].must.equal("[Circular ~]")
   })
 
+  it("must support array replacer", function() {
+    var obj = {name: "Alice", child: {name: "Bob", "": "Carol"}, "": "Dan"}
+    obj.child.self = obj.child
+
+    stringify(obj, ["name"], 2).must.eql(jsonify({
+      name: "Alice"
+    }))
+
+    stringify(obj, ["name", ""], 2).must.eql(jsonify({
+      name: "Alice",
+      "": "Dan"
+    }))
+
+    stringify(obj, ["child"], 2).must.eql(jsonify({
+      child: {}
+    }))
+
+    stringify(obj, ["child", ""], 2).must.eql(jsonify({
+      child: {
+        "": "Carol"
+      },
+      "": "Dan"
+    }))
+
+    stringify(obj, ["child", "", "self"], 2).must.eql(jsonify({
+      child: {
+        "": "Carol",
+        self: "[Circular ~.child]"
+      },
+      "": "Dan"
+    }))
+  })
+
   it("must call given decycler and use its output for nested objects",
     function() {
     var obj = {}