Reduce compilation (rewrite some classic collection methods using reduce)

reduce.js

/* From: https://medium.com/@hkairi/reduce-le-couteau-suisse-du-d%C3%A9veloppeur-javascript-8cf4b6f98304
1. min()
2. max()       
3. length()    
4. map()       
5. filter()   
6. reverse()  
7. unique()   
8. take() 
9. any()   
10. every()
*/

/* 1. min */
const MinAetB = (x, y) => x < y ? x : y
const min = (collection) => collection.reduce(MinAetB, collection[0]);

/* 2. max */
const MaxAetB = (a, b) =>  a > b ? a : b;
const max = (collection) => collection.reduce(MaxAetB, collection[0]);

/* 3. length */
const length = (collection) => collection.reduce((count, _) => count + 1, 0);

/* 4. map */
const map = 
  (fn, collection) => collection.reduce(
    (acc, item) => acc.concat( fn(item) ), 
  []);

/* 5. filter */
const filter = 
  (fn, collection) => collection.reduce(
    (acc, item) => fn(item) ? acc.concat(item) : acc, 
  []);
  
/* 6. reverse */
const reverse = 
  (collection) => collection.reduce(
    (acc, item) => [item].concat(acc), 
  []);
  
/* 7. unique */
const unique = 
  (collection) => collection.reduce(
    (acc, item) => { 
      if( collection.indexOf(item) === -1 ){
        return acc.concat(item);
      } else {
        return acc;
      }
    }, 
  []);
  
/* 8. take */
const take = 
  (nb, collection) => collection.reduce(
    (acc, item) => {
      if(nb > 0){
        nb--;
        return acc.concat(item);
      } else {
        return acc;
      }
    }, 
  nb);
  
/* 9. any */
const any = 
  (predicat, collection) => collection.reduce(
    (acc, item) => predicat(item) || acc,
   false); 
   
/* 10. every */
const every = 
  (predicat, collection) => collection.reduce(
    (acc, item) => predicat(item) && acc, 
  true);