optimize return undefined and return void 0

2015-10-28 13:25:27 -04:00
parent 335e349314
commit 7491d07666
2 changed files with 239 additions and 0 deletions
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -65,6 +65,7 @@ function Compressor(options, false_by_default) {
        keep_fnames   : false,
        hoist_vars    : false,
        if_return     : !false_by_default,
+        return_void_0 : !false_by_default,
        join_vars     : !false_by_default,
        cascade       : !false_by_default,
        side_effects  : !false_by_default,
@@ -2519,4 +2520,13 @@ merge(Compressor.prototype, {
    OPT(AST_Object, literals_in_boolean_context);
    OPT(AST_RegExp, literals_in_boolean_context);

+    OPT(AST_Return, function(self, compressor){
+        if (compressor.option("return_void_0")) {
+            if (self.value instanceof AST_Undefined) {
+                self.value = null;
+            }
+        }
+        return self;
+    });
+
 })();