createCtorWrapper.js
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define(['./baseCreate', '../lang/isObject'], function(baseCreate, isObject) {
/**
* Creates a function that produces an instance of `Ctor` regardless of
* whether it was invoked as part of a `new` expression or by `call` or `apply`.
*
* @private
* @param {Function} Ctor The constructor to wrap.
* @returns {Function} Returns the new wrapped function.
*/
function createCtorWrapper(Ctor) {
return function() {
// Use a `switch` statement to work with class constructors.
// See http://ecma-international.org/ecma-262/6.0/#sec-ecmascript-function-objects-call-thisargument-argumentslist
// for more details.
var args = arguments;
switch (args.length) {
case 0: return new Ctor;
case 1: return new Ctor(args[0]);
case 2: return new Ctor(args[0], args[1]);
case 3: return new Ctor(args[0], args[1], args[2]);
case 4: return new Ctor(args[0], args[1], args[2], args[3]);
case 5: return new Ctor(args[0], args[1], args[2], args[3], args[4]);
case 6: return new Ctor(args[0], args[1], args[2], args[3], args[4], args[5]);
case 7: return new Ctor(args[0], args[1], args[2], args[3], args[4], args[5], args[6]);
}
var thisBinding = baseCreate(Ctor.prototype),
result = Ctor.apply(thisBinding, args);
// Mimic the constructor's `return` behavior.
// See https://es5.github.io/#x13.2.2 for more details.
return isObject(result) ? result : thisBinding;
};
}
return createCtorWrapper;
});