_createCtor.js (1482B)
1 var baseCreate = require('./_baseCreate'), 2 isObject = require('./isObject'); 3 4 /** 5 * Creates a function that produces an instance of `Ctor` regardless of 6 * whether it was invoked as part of a `new` expression or by `call` or `apply`. 7 * 8 * @private 9 * @param {Function} Ctor The constructor to wrap. 10 * @returns {Function} Returns the new wrapped function. 11 */ 12 function createCtor(Ctor) { 13 return function() { 14 // Use a `switch` statement to work with class constructors. See 15 // http://ecma-international.org/ecma-262/7.0/#sec-ecmascript-function-objects-call-thisargument-argumentslist 16 // for more details. 17 var args = arguments; 18 switch (args.length) { 19 case 0: return new Ctor; 20 case 1: return new Ctor(args[0]); 21 case 2: return new Ctor(args[0], args[1]); 22 case 3: return new Ctor(args[0], args[1], args[2]); 23 case 4: return new Ctor(args[0], args[1], args[2], args[3]); 24 case 5: return new Ctor(args[0], args[1], args[2], args[3], args[4]); 25 case 6: return new Ctor(args[0], args[1], args[2], args[3], args[4], args[5]); 26 case 7: return new Ctor(args[0], args[1], args[2], args[3], args[4], args[5], args[6]); 27 } 28 var thisBinding = baseCreate(Ctor.prototype), 29 result = Ctor.apply(thisBinding, args); 30 31 // Mimic the constructor's `return` behavior. 32 // See https://es5.github.io/#x13.2.2 for more details. 33 return isObject(result) ? result : thisBinding; 34 }; 35 } 36 37 module.exports = createCtor;