Prefer jsesc for quoting

lib/utils/common.js

@@ -1,6 +1,7 @@
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+const jsesc = require('jsesc')
 const utils = require('../utils')
 
 class common extends utils {
@@ -30,28 +31,7 @@ class common extends utils {
   }
 
   static quote (s) {
-    // Taken from DOMfuzz
+    return jsesc(s)
-    function escapeString (s) {
-      return ('\"' + // eslint-disable-line no-useless-escape
-      s.replace(/\\/g, '\\\\')
-      .replace(/\"/g, '\\\"') // eslint-disable-line no-useless-escape
-      .replace(/\0/g, '\\0')
-      .replace(/\n/g, '\\n') +
-      '\"') // eslint-disable-line no-useless-escape
-    }
-
-    if (typeof s === 'string') {
-      if (/^[\n\x20-\x7f]*$/.exec(s) || !self.uneval) { // eslint-disable-line no-undef
-        // Printable ASCII characters and line breaks: try to make it pretty.
-        return escapeString(s)
-      } else {
-        // Non-ASCII: use uneval to get \u escapes.
-        return uneval(s) // eslint-disable-line no-undef
-      }
-    } else {
-      // For other things (such as numbers, |null|, and |undefined|), just coerce to string.
-      return JSON.stringify(s)
-    }
   }
 
   static b64encode (str) {