michabaur/ExtendingClass.js

## ExtendingClass.js
define(['yfiles/impl/graph-styles-core'], (yfiles) => {

  class ExtendingClass extends yfiles.styles.OMC {
    constructor() {
      super();
    }
  }

  return {ExtendingClass}
});

## test.html
<!DOCTYPE html>
<html>
<head>
  <title>Edge Constructor Issue</title>
</head>
<body>

<h1>Edge Constructor Issue</h1>

<script src="https://cdnjs.cloudflare.com/ajax/libs/require.js/2.3.2/require.min.js"></script>
<script>
  require.config({ baseUrl: 'http://live.yworks.com/yfiles-for-html/2.0/l-a61bcf8f42b1/' });
  require([
    './ExtendingClass.js'
  ], demoStyles => {
    let count = 0;
    let id = window.setInterval(() => {
      let style = new demoStyles.ExtendingClass();
      count++;
      if (count % 100 === 0) {
        document.getElementById('iteration').innerText = count;
      }
      if (!(style instanceof demoStyles.ExtendingClass)) {
        window.clearInterval(id);
        alert("Instance is not an instance of the right class. It worked " + count + " times before."
          + "\ntoString: " + style.toString()
          + "\ntypeof: " + typeof(style)
        );
      }
    }, 5)
  });
</script>

<p>The test starts automatically. New instances are continuously created until an error is detected.</p>

<p>Iteration Count: <span id="iteration">0</span> ...</p>

<p>In Edge 40.15025.1000.0, this works fine until you open the dev tools. Then, the error is triggered after several
  seconds (~5s) and our alert dialog is show.</p>

<p>If the dev tools are already open when the page is loaded, the error is not triggered until you close and re-open
  them.</p>

</body>
</html>
	define(['yfiles/impl/graph-styles-core'], (yfiles) => {

	class ExtendingClass extends yfiles.styles.OMC {
	constructor() {
	super();
	}
	}

	return {ExtendingClass}
	});
	<!DOCTYPE html>
	<html>
	<head>
	<title>Edge Constructor Issue</title>
	</head>
	<body>

	<h1>Edge Constructor Issue</h1>

	<script src="https://cdnjs.cloudflare.com/ajax/libs/require.js/2.3.2/require.min.js"></script>
	<script>
	require.config({ baseUrl: 'http://live.yworks.com/yfiles-for-html/2.0/l-a61bcf8f42b1/' });
	require([
	'./ExtendingClass.js'
	], demoStyles => {
	let count = 0;
	let id = window.setInterval(() => {
	let style = new demoStyles.ExtendingClass();
	count++;
	if (count % 100 === 0) {
	document.getElementById('iteration').innerText = count;
	}
	if (!(style instanceof demoStyles.ExtendingClass)) {
	window.clearInterval(id);
	alert("Instance is not an instance of the right class. It worked " + count + " times before."
	+ "\ntoString: " + style.toString()
	+ "\ntypeof: " + typeof(style)
	);
	}
	}, 5)
	});
	</script>

	<p>The test starts automatically. New instances are continuously created until an error is detected.</p>

	<p>Iteration Count: <span id="iteration">0</span> ...</p>

	<p>In Edge 40.15025.1000.0, this works fine until you open the dev tools. Then, the error is triggered after several
	seconds (~5s) and our alert dialog is show.</p>

	<p>If the dev tools are already open when the page is loaded, the error is not triggered until you close and re-open
	them.</p>

	</body>
	</html>