converge

Accepts a converging function and a list of branching functions and returns a function that applies each branching function to the arguments and the results of the branching functions are passed as arguments to the converging function.

• Use Array.prototype.map() and Function.prototype.apply() to apply each function to the given arguments.
• Use the spread operator (...) to call converger with the results of all other functions.

const converge = (converger, fns) => (...args) =>
  converger(...fns.map(fn => fn.apply(null, args)));

const average = converge((a, b) => a / b, [
  arr => arr.reduce((a, v) => a + v, 0),
  arr => arr.length
]);
average([1, 2, 3, 4, 5, 6, 7]); // 4