fixes #206, add checking for unary ops

lib/runtime/dart/convert.js

 var convert = dart.defineLibrary(convert, {});
 var core = dart.import(core);
 var async = dart.import(async);
 var typed_data = dart.import(typed_data);
 var _internal = dart.import(_internal);
 var collection = dart.import(collection);
 (function(exports, core, async, typed_data, _internal, collection) {
   'use strict';
   let Codec$ = dart.generic(function(S, T) {
     class Codec extends core.Object {
@@ skipping 1186 matching lines @@
           throw new JsonUnsupportedObjectError(object);
         }
         this[_removeSeen](object);
       } catch (e) {
         throw new JsonUnsupportedObjectError(object, {cause: e});
       }
 
     }
     writeJsonValue(object) {
       if (dart.is(object, core.num)) {
-        if (dart.dsend(dart.dload(object, 'isFinite'), '!'))
+        if (!dart.notNull(dart.as(dart.dload(object, 'isFinite'), core.bool)))

[Jennifer Messerly, 2015/06/04 00:16:23]

we'll probably want to do something about the nonNull as bool pattern of checks
...

           return false;
         this.writeNumber(dart.as(object, core.num));
         return true;
       } else if (core.identical(object, true)) {
         this.writeString('true');
         return true;
       } else if (core.identical(object, false)) {
         this.writeString('false');
         return true;
       } else if (object == null) {
@@ skipping 1672 matching lines @@
   exports.LineSplitter = LineSplitter;
   exports.StringConversionSink = StringConversionSink;
   exports.ClosableStringSink = ClosableStringSink;
   exports.UNICODE_REPLACEMENT_CHARACTER_RUNE = UNICODE_REPLACEMENT_CHARACTER_RUNE;
   exports.UNICODE_BOM_CHARACTER_RUNE = UNICODE_BOM_CHARACTER_RUNE;
   exports.Utf8Codec = Utf8Codec;
   exports.UTF8 = UTF8;
   exports.Utf8Encoder = Utf8Encoder;
   exports.Utf8Decoder = Utf8Decoder;
 })(convert, core, async, typed_data, _internal, collection);