A little demonstration of Ramda

demo.js

import * as R from 'ramda'

// Setting up some date to play with
const foo = {
  validate() {
    return this.x < 69 && (typeof this.name === 'string');
  },
  x: 420,
  name: Symbol('lul')
}
const bar = {
  validate() {
    return this.value > 0 && this.id !== undefined;
  },
  id: 2,
  value: 42
}

const components = [foo, bar]

// Old-school approach: use a for loop
function withForLoop(){
  const result = [];
  for(let i = 0; i < components.length; i++){
    result.push(components[i].validate());
  }
  return result;
}

//Map is much more concise
function withMap(){
  return components.map(comp => comp.validate())
}

// Using an invoker means no need for the arrow function
const validate = R.invoker(0, 'validate');
function withInvoker(){
  return components.map(validate)
}

// Using a partially applied map just gives us a function that validates lists of components.
const validateAll = R.map(validate)
function withFullRamda(){
  return validateAll(components)
}

// To check if all elements in a list are equal:
const allEqual = ([x, ...xs]) => R.all(R.equals(x), xs)

allEqual([
  withForLoop(),
  withMap(),
  withInvoker(),
  withFullRamda()
])