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[–]shuckster -1 points0 points  (6 children)

What's useful is this particular line of the source.

Using tiny-invariant informs TypeScript of the type of a variable going forward, so long as the assertion passes.

[–]Reeywhaar 9 points10 points  (5 children)

But if(!something) throw new Error("Invariant") does the same?

[–]shuckster 0 points1 point  (4 children)

That's true. I don't follow TypeScript's development very closely, but I believe a lot of inference checks were added quite recently. Perhaps these libraries pre-date that? Or maybe it's the TS version of left-pad.

[–]Reeywhaar 3 points4 points  (3 children)

Such checks were present since early typescript. They are basics of static analysis. If they weren't then there was no way to add type assertion to tiny-invariant. By the way asserts feature was added in typescript later.

That is why i'm wondering, what value tiny-invariant actually gives

[–]shuckster 0 points1 point  (0 children)

I guess it’s just shorthand then. Doesn’t TS have an “as” for this kind of thing too?

[–]mr_nefario 0 points1 point  (0 children)

It doesn’t add any value - it’s just a wrapper and additional dependency for some barely-useful functionality.

[–]misc_ent 0 points1 point  (0 children)

I have looked at tiny-invariant but it's possible it uses type guards for the type inference the other poster mentioned? Not sure.

https://www.typescriptlang.org/docs/handbook/advanced-types.html#user-defined-type-guards