Some functional programming functions

functional.js

const SORT_STRATEGIES = {
  asc: (a, b) => (a - b > 0 ? 1 : -1),
  desc: (a, b) => (a - b < 0 ? 1 : -1),
};

const pipe = (...fns) =>
  fns.reduce(
    (f, g) =>
      (...args) =>
        g(f(...args))
  );

const map =
  (...funcs) =>
  (arr) =>
    arr.map(pipe(...funcs));

const filter =
  (...funcs) =>
  (arr) =>
    arr.filter((val) => funcs.every((func) => func(val)));

const sortBy =
  (key = false, ascOrDesc = "asc") =>
  (arr) => {
    return [...arr].sort((a, b) =>
      SORT_STRATEGIES[ascOrDesc](key ? a[key] : a, key ? b[key] : b)
    );
  };

const take = (x) => (arr) => arr.slice(0, x);