JS, at its core is a dynamically typed, functional language. Typescript aims to model a strongly typed, OPP language. The two programming paradigms have their own strengths, weaknesses and most importantly: patterns and best practices.
If the only difference between your pure javascript code and your typescript code is the annotations, you are doing it wrong.
Do you think? I just take TS for what it gives me, documentation and static code analysis. I can write down my knowledge and expectations about the code and have the tool keep track of it for me, removing the cognitive load of doing it myself- which I'd have to otherwise.
Can you give me an example of a pattern that is "good" in JS and not in TS, or the other way round? I'm curious.
When using TS the class syntax fits in perfectly for me, an in pure JS I'd stick to functions.
That's a rather puzzling statement, to be honest. Strong type system is explicitly one of the non-goals[0]. I write typescript code everyday and most of it is functional. Things like fp-ts[1] make it even more enjoyable.
[0] https://github.com/Microsoft/TypeScript/wiki/TypeScript-Desi... [1] https://github.com/gcanti/fp-ts
What I meant by the comment is that when using TS, I just find it more easy and natural to go with the proper OOP approach. I think the very existence of a separate library to enable a more functional style in TS proves this goal has not been met yet.
Why don't I consider it strongly typed?: Structurally subtyped as opposed to nominal typing, the pervasiveness of any, allowance for vanilla JS coercion, exceptions and promise rejections are untyped, etc.