Simplify jsify and dartify

Author: kevmoo

lib/src/interop/js_interop.dart

@@ -5,6 +5,3 @@ import 'package:js/js.dart';
 
 @JS("JSON.stringify")
 external String stringify(obj);
-
-@JS("JSON.parse")
-external dynamic parse(s);

lib/src/utils.dart

@@ -3,6 +3,7 @@ import 'dart:convert';
 
 import 'package:func/func.dart';
 import 'package:js/js.dart';
+import 'package:js/js_util.dart' as util;
 
 import 'interop/firebase_interop.dart';
 import 'interop/js_interop.dart' as js;
@@ -13,6 +14,10 @@ dynamic dartify(Object jsObject) {
     return jsObject;
   }
 
+  if (jsObject is List) {
+    return jsObject.map(dartify).toList();
+  }
+
   var json = js.stringify(jsObject);
   return JSON.decode(json);
 }
@@ -23,13 +28,7 @@ dynamic jsify(Object dartObject) {
     return dartObject;
   }
 
-  Object json;
-  try {
-    json = JSON.encode(dartObject, toEncodable: _noCustomEncodable);
-  } on JsonUnsupportedObjectError {
-    throw new ArgumentError("Only basic JS types are supported");
-  }
-  return js.parse(json);
+  return util.jsify(dartObject);
 }
 
 /// Returns [:true:] if the [value] is a very basic built-in type - e.g.
@@ -41,9 +40,6 @@ bool _isBasicType(value) {
   return false;
 }
 
-_noCustomEncodable(value) =>
-    throw new UnsupportedError("Object with toJson shouldn't work either");
-
 /// Handles the [thenable] object.
 Future<T> handleThenable<T>(ThenableJsImpl<T> thenable) {
   var completer = new Completer<T>();