There are actually two important components to consider:
The compilation aspect. Typings are required for this part, which are now included in the core-js typings.
The execution aspect. To fully execute the code, you must ensure that Reflect.js
is added to your main HTML page.
<script src="node_modules/zone.js/dist/zone.js"></script>
<script src="node_modules/reflect-metadata/Reflect.js"></script> <----
<script src="node_modules/systemjs/dist/system.src.js"></script>
By following these steps, you will be able to utilize Reflect.getMetadata()
within your code.