Pattern Matching in TypeScript

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21 pointsfatih-erikli7 comments

Looks like you've done some homework here.

Just a quick note: I followed through to the article on https://fatih-erikli.com/pattern-matching-in-typescript.html and noticed the useEffect call doesn't define a dependency array (not even an empty one), which I believe will make the addEventListener add new listeners on every render. Having a removeEventListener on the return of the useEffect would also ensure it gets cleaned up, if pointed to the same event name / handler.

I assume it was just for illustrative purposes, but felt like I should point it out, regardless.

Yes it was for illustrative purposes, thanks for reading the article :)

To be honest this is more like a Typescript project and example rather than React. I'm learning Typescript and this is how I try to improve my understanding of Generic types.

eventEmitter.addEventListener returns a unsubscribe function to remove the event listeners. useEffect hook calls the passed function's return value if it is not a void.

https://reactjs.org/docs/hooks-effect.html#example-using-hoo...

So my eventEmitter.addEventListener method in the blog post returns an ubsubscriber when you call it :)

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