Only last parameter between parentheses can have spread

lib/parse.js

@@ -1163,12 +1163,16 @@ function parse($TEXT, options) {
         while (!is("punc", ")")) {
             if (first) first = false; else expect(",");
             if (is("expand", "...")) {
+                var spread_token = S.token;
                 next();
                 a.push(new AST_Expansion({
                     start: prev(),
                     expression: as_symbol(AST_SymbolFunarg),
                     end: S.token,
                 }));
+                if (!is("punc", ")")) {
+                    unexpected(spread_token);
+                }
             } else {
                 a.push(expression(false));
             }