I have a feeling you made up "x/2 hours every single day".
If you're prone to making easy to avoid errors in your code, then maybe Typescript will save you time. For me, that is not the case. YMMV.
But it's worth it because you're about to get a massive multiplier effect based on the scale of your user base.
So what if I'm not a "library author", what I do could still be non-trivial, and I could still do it without typescript like people have been doing for decades before. Typescript is not the only strong-typing game in javascript town.
>But it's worth it because you're about to get a massive multiplier effect based on the scale of your user base.
Using typescript is not a causal factor for this. What the library does, and what people need is.
And honestly I don't care who is using a library I make, life isn't all about likes and it isn't a popularity contest.
Anyway, this gets off-track. The metric is (time wasted on problems that only exist without typing) / (time it takes to configure TypeScript). Regardless of what your 10% figure is, learning TypeScript and configuring it for a project takes less time.
> If you're prone to making easy to avoid errors in your code, then maybe Typescript will save you time. For me, that is not the case. YMMV.
Putting aside the dig, it sounds like you're working alone, so use whatever you want. It matters a lot less when you control the data structures and hold the entire program in your own head.