29Implement compose() and pipe()

Implement two helpers that chain functions:

• pipe(f, g, h) returns a function that runs f, then g, then h: h(g(f(...args))). Left to right, like reading a recipe.
• compose(f, g, h) runs right to left: f(g(h(...args))). This is the mathematical order, used by Redux's compose.

const slugify = pipe(
  (s) => s.trim(),
  (s) => s.toLowerCase(),
  (s) => s.replace(/\s+/g, "-"),
);
slugify("  Hello World "); // "hello-world"

const add = (a, b) => a + b;
const double = (n) => n * 2;
compose(double, add)(2, 3); // 10

Requirements

• The first function to run may take several arguments; every later one receives the previous result.
• With no functions, return the identity function (x => x).
• Throw a TypeError when creating the chain if any argument is not a function, not later when it runs.