18-6 Anagram - The anagram function fails to test for duplicate values or empty values

[fewdn]

https://github.com/bradtraversy/javascript-sandbox/blob/main/18-unit-testing-algorithms/06-anagrams/algo-testing/anagram/anagram.js

The updated file can be found here:
PacktPublishing#3

The anagram function should return false if both words are the same or when one or both strings are empty.
Of course more could be done to remove special characters & numbers to clean the incoming values.

Currently invoking the following returns true but should be false:

anagram("pop", "pop");
anagram("", "");
anagram(" ", " ");

The quick fix could be a conditional and remove whitespace with replaceAll().

 const cleanStr1 = str1.replaceAll(" ", "").toLowerCase();
 const cleanStr2 = str2.replaceAll(" ", "").toLowerCase();
  if ( str1 === str2 ) { return false; }

Or, clean the string of special characters, numbers & whitespace, using a Regular Expression, then compare:

const pattern = /^[^A-Za-z]+/g;
const cleanStr1 = str1.replaceAll(pattern, "").toLowerCase();
const cleanStr2 = str2.replaceAll(pattern, "").toLowerCase();

if (cleanStr1 === cleanStr2) { return false; }