Java-script strtr — translate characters or replace substrings

strtr.js

/**
* strtr() for JavaScript
* Translate characters or replace substrings
*
* @author Dmitry Sheiko 
* @version strtr.js, v 1.0.2 
* @license MIT
* @copyright (c) Dmitry Sheiko http://dsheiko.com
**/

String.prototype.strtr = function ( dic ) { 
  const str = this.toString(),
        makeToken = ( inx ) => `{{###~${ inx }~###}}`,
        
        tokens = Object.keys( dic )       
          .map( ( key, inx ) => ({
            key,
            val: dic[ key ],
            token: makeToken( inx )
          })),
            
        tokenizedStr = tokens.reduce(( carry, entry ) => 
          carry.replace( new RegExp( entry.key, "g" ), entry.token ), str );
          
  return tokens.reduce(( carry, entry ) => 
          carry.replace( new RegExp( entry.token, "g" ), entry.val ), tokenizedStr );
};

// Test
console.log("{palceholder}, I said hello".strtr({
    "{palceholder}" : "Molly",     
    "hello" : "grüß dich"
}));
console.log("{palceholder}, I said hello".strtr({
    "{palceholder}" : "hello",     
    "hello" : "grüß dich"
}));

You will get wrong result if function changes a part, than that part will match with a next key again.
For example:

   "{palceholder}" : "hello",     
    "hello" : "grüß dich"

You will get grüß dich instead of hello in {palceholder}'s place.

Dosen't work ((

var str  = '[test]';
var result = str.strtr({'[':'-',']':'-'});

Error: Uncaught SyntaxError: Invalid regular expression: /[/: Unterminated character class

A better version, resolve @csimpi issue:

const escapeRE = require('lodash.escaperegexp')
const strtr = (str, pairs) => {
  const substrs = Object.keys(pairs).map(escapeRE)
  return str.split(RegExp(`(${substrs.join('|')})`))
            .map(part => pairs[part] || part)
            .join('')
}

Opps, I was not even aware I have comments on that. Sorry, Thank you guys, the mentioned issues are valid. I've just updated the gist with the fix

this only replace each pair of words once

@SnowyYANG You're right. I updated the snippet.