Internalize Date when time package not imported in a reasonable way.

dmitshur · dmitshur · commit dfffae765dbb · 2015-08-30T01:26:21.000-07:00
Fixes #279 (additional findings). When time package is not imported, it's still possible to internalize a Date object (into an interface{}). Due to fallthrough being default, this resulted in Function case running when internalizing Date with no time package. That makes no sense, and means that trying to externalize the Date object back into JavaScript world would fail to produce the original Date object (also, calling methods on it would obviously fail, since it's not a real Date object). For example, consider the following code that doesn't import time package, it can now run and produce expected results: date := js.Global.Get("Date").New().Interface() js.Global.Get("console").Call("log", date)
diff --git a/compiler/prelude/jsmapping.go b/compiler/prelude/jsmapping.go
@@ -273,6 +273,9 @@ var $internalize = function(v, t, recv) {
       var timePkg = $packages["time"];
       if (timePkg) {
         return new timePkg.Time(timePkg.Unix(new $Int64(0, 0), new $Int64(0, v.getTime() * 1000000)));
+      } else {
+        /* time package is not present, internalize as &js.Object{Date} so it can be externalized into original Date. */
+        return new $jsObjectPtr(v);
       }
     case Function:
       var funcType = $funcType([$sliceType($emptyInterface)], [$jsObjectPtr], true);
