collections.js

// includes-all
needles.map((elem) => haystack.includes(elem)).reduce((found, curr) => found && curr);

// includesAny
needles.some((elem) => haystack.includes(elem));

// includesNone
!needles.some((elem) => haystack.includes(elem));

// mapNotNullish
arr.filter(i => i).map(() => {});

// takeFirstWhile
firsts = original.slice(original.findIndex((i) => {}));

// takeLastWhile
lasts = original.slice(original.findIndex((i) => {}) - original.length);

// dropFirstWhile & dropLastWhile are just aliases for the previous 2

// sortBy
arr.sort((a, b) => a.age < b.age);

// without
arr.filter((n) => n !== 13);

// withoutAll
arr.filter((n) => !needles.includes(n));

// firstNotNullishOf
arr.filter(i => i)[0];

// sumOf
arr.reduce((accumulator, current) => accumulator += current.age);

// maxBy & minBy
arr.reduce((accumulator, current) => {
  if (accumulator.age < current.age) {
    accumulator = current;
  }
});

// maxWith & minWith
let numbers = [
  [ 1, 3, 4 ],
  [ 6, 1, 3 ],
  [ 4, 5, 2 ],
];
const sum = (acc, curr) => acc += curr;
arr.reduce((accumulator, current) => {
  if (accumulator.reduce(sum) < current.reduce(sum)) {
    accumulator = current;
  }
});

// maxOf & minOf
arr.reduce((accumulator, current) => accumulator = Math.max(accumulator, current.age));

// average
arr.reduce((accumulator, current) => accumulator += current) / arr.length;

// associateBy
arr.map((i) => {
  return { i.id: i };
});