30-seconds-of-code/snippets/bindKey.md

bindKey

Creates a function that invokes the method at a given key of an object, optionally adding any additional supplied parameters to the beginning of the arguments.

Return a function that uses Function.apply() to bind context[fn] to context. Use Array.concat() to prepend any additional supplied parameters to the arguments.

const bindKey = (context, fn, ...args) =>
  function() {
    return context[fn].apply(context, args.concat(...arguments));
  };

const freddy = {
  user: 'fred',
  greet: function(greeting, punctuation) {
    return greeting + ' ' + this.user + punctuation;
  }
};
const freddyBound = bindKey(freddy, 'greet');
console.log(freddyBound('hi', '!')); // 'hi fred!'