implementing Function.prototype.bind

bind.js

Function.prototype.bind = function (context) {
    if (typeof this !== 'function') {
        throw new TypeError("Function.prototype.bind - what is trying to be bound is not callable");
    }
    var fn    = this, // the function to bind
        slice = Array.prototype.slice // cache slice method
        args  = slice.call(arguments, 1), // get the array of addtional arguments (to be curried)
        noop = function () {}, // the intermediate function to serve as a prototype chain connector
                               // (assuming we don't have Object.create() here)
        bound = function () {
            var ctx = this instanceof noop && context
                ? this
                : context
            return fn.apply(ctx, args.concat(slice.call(arguments)))
        }
    // inherit the prototype of the to-be-bound function
    noop.prototype = fn.prototype
    bound.prototype = new noop()
    return bound
}

test.js

function Test (arg) {
    return this.value + arg
}

var obj = {
    value: 123
},
test = Test.bind(obj)

console.log(test(345) === (123 + 345))

different approach:

Function.prototype.bind = function bind(funcThis, ...params) {
  if (typeof this !== 'function') {
    throw new Error("can't run bind function on non-functions")
  }
  const newFunc = (...aditionalParams) => this.call(funcThis, ...params, ...aditionalParams)
  newFunc.bind = (...aditionalParams) => bind.call(this, funcThis, ...params, ...aditionalParams.slice(1))
  return newFunc
}