This is a simple script to show how you can implement functional style JavaScript.

anagrams.js

// Just a short hand function to assist the push function, it simply 
// turns a string into an array, and due to surrogate pairs, 
// this solution removes all instances of null, then it sorts the array, 
// and finally returns it as a string.
const sort = s => [...s].filter(x => x != null).sort().join('');


// A function that will assist the anagrams function, it will 
// essentially state whether or not to push a string onto the 
// anagrams array or to push null onto the array, there are times
// where this code needs to push null onto the array. But it's okay, 
// thanks to the anagrams function, the array gets stripped of all 
// null value(s).
const push = o => w => sort(o) === sort(w) && o != w ? o : null;


// A function that takes one argument, which is some dictionary,
// it then returns a function that takes string, to find the 
// anagrams that are within the provided dictionary, it then produces 
// an array of anagrams.
const anagrams = d => w => d.map(o => push(o)(w)).filter(s => s != null);
  
	

// Define some random dictionary and search that dictionary with some 
// random string to get back some anagrams, then print the results. All
// of these values are being stored into some variabels, although this is
// just a demonstration of how it works. 
const dictionary = ['sign','sing','gins','snig','ings','sgin','sngi','𝟘𝟙𝟚𝟛'];
const word = 'gins';
const odd = '𝟛𝟚𝟙𝟘';
const results = anagrams(dictionary)(word);
const oddCharResult = anagrams(dictionary)(odd);
console.log(results);
console.log(oddCharResult);