New Keyword Not Required for UI Component Javascript Objects

In doing research for the new uElement Internals series, I discovered that Magento’s UI Component object constructors (uiClass, uiElement, uiCollection, etc) can create new objects without the use of the new keyword.

//both return a new `UiElement` object
object = new UiElement;
object = UiElement();

This makes these constructor objects closer in behavior to Magento’s base helper classes like Object and Array. It is curious, however, that the view model registration code

#File: vendor/magento//magento2-base/lib/web/mage/layout.js
function initComponent(node, Constr) {    
    var component = new Constr(_.omit(node, 'children'));

    registry.set(node.name, component);
}

choses to use the new keyword when instantiating these objects. Perhaps it’s a sign that there’s multiple developers not talking to one another, or that there’s weird bugs/differences when using or not using the new keyword. One is, once again, left in the dark without decent documentation on the subject.