JSFiddle - React, Tailwind, and code Playground

HTML

<html>
<body>
    <p>In this test we need to find out if the browser can save the localStorage item correctly without truncated by the \x00 in the middle of the string.</p>
<script type="text/javascript">
    var key = 'TruncVal';
    var value = '123\x00567';

    var x = localStorage.getItem(key);
    if (!x) {
	        localStorage.setItem(key, value);
	        document.write("<p>It hasn't got the '" + key + "' in the localStorage database, will create it using:<br>");
	        document.write("<code>localStorage.setItem('" + key + "', '" + value + "');</code><br>");
	        document.write("Now close your browser and start it again to see the results.</p>");
	    }
	    else {
	        document.write("<p>The value of " + key + " is: '" + x + "', the length is: " + x.length + "<br>");
	
	        if (x == value) {
	            document.write("PASS.");
	        }
	        else {
	            document.write("FAIL: The expected value is: '" + value + "', the expected length is: " + value.length);
	        }
	        document.write("</p><a href=\"javascript:localStorage.removeItem('" + key + "');\">remove '" + key + "' from localStorage</a>");
	    }
	</script>
	
	<p>This is for <a href="https://bugs.webkit.org/show_bug.cgi?id=58762">https://bugs.webkit.org/show_bug.cgi?id=58762</a>
	</p>
	</body>
	</html>