Current firefox version: 83.0 (64-bit)
Firefox Nightly version：85.0a1 (2020-11-29) (64-bit)
In the latest Nightly version, the combination of aria-live on firefox + voiceOver is fixed! 🎉 Hooray!
Reference: Firefox/Voiceover: aria-live regions not being announced
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Aria-live Demo</title>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/2.1.3/jquery.min.js"></script>
<style>
body {
margin: 1em;
}
button {
margin-top: 1em;
display: block;
}
</style>
</head>
<body>
<h1>Aria-live Demo</h1>
<p>Testing <code>aria-live</code><br><button>Add Content</button><button id="add-more" >Add more content</button></p>
<!-- add aria-live="polite" -->
<div class="target" aria-live="polite" ></div>
<script type="text/html" id="test-content">
<h2>Custom Content</h2>
<p>Hello there! I am content that is going to be plunked into a container via javascript</p>
</script>
<input placeholder="messgae somebody"/>
<script>
$("button").on("click", function(){
$(".target").html($("#test-content").html());
});
$("#add-more").on("click", function(){
$(".target").append("<p>Hello World</p>");
});
$(document).on("keydown", function(e){
// press space to add content
if(e.keyCode === 32) {
$(".target").append("<p>Hello World</p>");
}
});
</script>
</body>
</html>