Escape '"' and "\" in a string with literal

Author: danny0838

parse-css.js

@@ -780,13 +780,12 @@ function escapeString(string) {
   // Escapes the contents (between the quotes) of a string
   return Array.from(String(string), e=>{
     const code = e.codePointAt(0);
-    if(between(code, 0x0, 0x1f)
-      || code == 0x7f
-      || code == 0x22
-      || code == 0x5c
-    ) {
+    if(between(code, 0x0, 0x1f) || code === 0x7f) {
       return "\\" + code.toString(16) + " ";
     }
+    if(code === 0x22 || code === 0x5c) {
+      return "\\" + String.fromCodePoint(code);
+    }
     return e;
   }).join("");
 }