strict encodeURIComponent for Firebase

encodeURIComponentForFirebase.js

// Strict escaping symbols not accepting by Firebase.
// https://www.firebase.com/docs/web/guide/understanding-data.html#section-creating-references
// Data Limits - A child node's key cannot be longer than 768 bytes, nor deeper than 32 levels.
// It can include any unicode characters except for . $ # [ ] / and ASCII control characters 0-31 and 127.

function encodeURIComponentForFirebase(str) {
  return encodeURIComponent(str).replace(/[\.\#\$\[\]]/g, function (c) {
    return '%' + c.charCodeAt(0).toString(16);
  });
},