Function composition in JavaScript

function-composition.js

// https://www.codementor.io/michelre/use-function-composition-in-javascript-gkmxos5mj
function compose(...functions) {
  return args => functions.reduceRight((arg, fn) => fn(arg), args);
}

const cntk = {
  c1(input, options = {}) {
    // console.log('c1', input, options);
    return 'c1: ' + input;
  },
  c2(input, options = {}) {
    // console.log('c2', input, options);
    return 'c2: ' + input;
  }
};

compose(
  input => cntk.c1(input, { foo: true }), // partial application to pass in static options
  cntk.c2
)('asdf'); // 'asdf' is input to the first function
// 'c1: c2: asdf'