:focus selector bug for Firefox

The focus selector fails for input type=file. Tab through the inputs. Works for all other types.

HTML

<body>
		<div>
			<header>
				<h1>HTML inputs</h1>
			</header>
          <div>
				<form action="">
					<fieldset>
						<legend></legend>
						<div><label for="input_1">Input type text</label><input type="text" id="input_1" /></div>
						<div><label for="input_2">Input type search</label><input type="search" id="input_2" /></div>
						<div><label for="input_3">Input type tel</label><input type="tel" id="input_3" /></div>
						<div><label for="input_4">Input type url</label><input type="url" id="input_4" /></div>
						<div><label for="input_5">Input type email</label><input type="email" id="input_5" /></div>
						<div><label for="input_6">Input type date</label><input type="date" id="input_6" /></div>
						<div><label for="input_17">Input type file</label><input type="file" id="input_17" /></div>
						<div><label for="input_7">Input type month</label><input type="month" id="input_7" /></div>
						<div><label for="input_8">Input type week</label><input type="week" id="input_8" /></div>
						<div><label for="input_9">Input type time</label><input type="time" id="input_9" /></div>
						<div><label for="input_10">Input type date/time</label><input type="datetime" id="input_10" /></div>
						<div><label for="input_11">Input type local date/time</label><input type="datetime-local" id="input_11" /></div>
						<div><label for="input_12">Input type number</label><input type="number" id="input_12" /></div>
						<div><label for="input_13">Input type range</label><input type="range" id="input_13" /></div>
						<div><label for="input_14">Input type color</label><input type="color" id="input_14" /></div>
						<div><label for="input_15">Input type checkbox</label><input type="checkbox" id="input_15" /></div>
						<div><label for="input_18">Input type radio button</label><input type="radio" id="input_18" /></div>
						<div><label for="input_16">Input type image</label><input type="image" id="input_16" /></div>
						<input type="button" value="button"...

JavaScript

$(function(){ 
    $("fieldset").on("keydown.tabTest", "input", function (e) {
        var jqf = $(":focus").after("J"), 
            jqda = $(document.activeElement).after("D"),
            jqfc = $(document.querySelector(":focus")).after("F"),
            jqfa = $(document.querySelector(":active")).after("A");
		console.log(jqf, jqda, jqfc, jqfa);
	});
});