Fix internalize case for undefined value.

dmitshur · dmitshur · commit bf81f3863f6c · 2015-06-07T20:41:27.000-07:00
Fixes #237.
diff --git a/compiler/prelude/jsmapping.go b/compiler/prelude/jsmapping.go
@@ -245,6 +245,9 @@ var $internalize = function(v, t, recv) {
     if (v === null) {
       return $ifaceNil;
     }
+    if (v === undefined) {
+      return new $jsObjectPtr(undefined);
+    }
     switch (v.constructor) {
     case Int8Array:
       return new ($sliceType($Int8))(v);
diff --git a/js/js_test.go b/js/js_test.go
@@ -309,6 +309,16 @@ func TestUndefinedEquality(t *testing.T) {
 	}
 }
 
+func TestUndefinedInternalization(t *testing.T) {
+	undefinedEqualsJsUndefined := func(i interface{}) bool {
+		return i == js.Undefined
+	}
+	js.Global.Set("undefinedEqualsJsUndefined", undefinedEqualsJsUndefined)
+	if !js.Global.Call("eval", "(undefinedEqualsJsUndefined(undefined))").Bool() {
+		t.Fail()
+	}
+}
+
 func TestSameFuncWrapper(t *testing.T) {
 	a := func(_ string) {} // string argument to force wrapping
 	b := func(_ string) {} // string argument to force wrapping
