Angular2 using either npm reflect-metadata or core-js/es7/reflect

Question

Looking at Angular2 projects, I see some are using: npm reflect-metadata

and others are using : core-js/es7/reflect

I know both are implementing the ES7 proposed Decorator and reflect API

But what is the difference between the two? Are they just copy/paste ? I assume they are equivalent

Answer 1

core-js/es7/reflect: The native JavaScript support for a metadata reflection API.

npm reflect-metadata: The TypeScript support for the prototype of the ES7 Reflection API.

Hope this help!