title: bindKey tags: function,object,intermediate

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.prototype.apply() to bind context[fn] to context. Use the spread operator (...) to prepend any additional supplied parameters to the arguments.

const bindKey = (context, fn, ...boundArgs) => (...args) =>
  context[fn].apply(context, [...boundArgs, ...args]);

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