Modernizr.load Deprecated. Yepnope.js Deprecated. Now what? - conditional-statements

Question

Prior to Modernizr v3, I was using yepnope.js
Modernizr.load and yepnope.js have both been deprecated. How do we conditionally call stylesheets or javascript files now?
Example that worked with Modernizr v2.5.3:
Modernizr.load({
test: Modernizr['object-fit'],
nope: ['./dist/scripts/object-fit.js'],
complete: function(){
if (!Modernizr['object-fit']) {
jQuery(".poster img").imageScale({
scale: "best-fill",
rescaleOnResize: true
});
}
}
});

Answer 1

There's a new syntax and the feature names are all lowercase. You can combine that with jQuery's getScript method.
Which would look something like this:
if (Modernizr.objectfit){
jQuery.getScript("./dist/scripts/object-fit.js")
//it worked! do something!
.done(function(){
console.log('js loaded');
})
//it didn't work! do something!
.fail(function(){
console.log('js not loaded');
});
} else {
jQuery(".poster img").imageScale({
scale: "best-fill",
rescaleOnResize: true
});
}

Answer 2

Have a look here for scripts: https://stackoverflow.com/a/7719185 — no jQuery required. (Note that there's a shorter Promise example a bit down in the answer; don't stop reading after the first example (like I did)).
And here for CSS: loadCSS: https://github.com/filamentgroup/loadCSS/blob/master/src/loadCSS.js
— this is, in a way, even better than YepNope.js, if you don't need any of its features except for just loading stuff + callback. Because the stuff linked above, is smaller (smaller min.js.gz) than yepnope.js.
(And can combine with Modernizr like mhk showed in his answer.)