ES6 JavaScript Compose Function

Definition

const compose = (...fns) =>
  fns.reverse().reduce((prevFn, nextFn) =>
    value => nextFn(prevFn(value)),
    value => value
  );

Example

Create the function, composed of three others:

const example = compose(
  val => { console.log(1); return `1<${val}>`; },
  val => { console.log(2); return `2<${val}>`; },
  val => { console.log(3); return `3<${val}>`; }
);

Call the function:

x('hello')

Console output is:

3
2
1
"1<2<3<hello>>>"