On: I Was Wrong About TypeScript

[shuzchen]

I was just about to complain how TS fails totally for typechecking backbone models or immutablejs datastructures: both situations where obj.get("foo") and obj.get("bar") return a particular type but there's no way of having TS handle that except defining them as any. But it turns out string literal types in 1.8 will make that work. And this was out since February! I should reevaluate TS for my omniscient project.

[danielearwicker → shuzchen]

The example you give has been supported since day 1. Example: document.createElement("canvas") returns HTMLCanvasElement. A limited form of string literal types has always been supported specifically for overloading return types. The newer support added in 1.8 is a way more powerful generalisation.

[rubber_duck → shuzchen]

IIRC there is no ergonomic way to define typed records for Immutable.js ?

[girvo → rubber_duck]

If I recall correctly, you still can't type Immutable.js nicely with Flow, let alone Typescript, so I'm not surprised tbh

[danielearwicker → rubber_duck]

I've been playing with https://github.com/danielearwicker/doop

[nidu → shuzchen]

It could also benefit from constant propagation (iirc the term) where you could write obj.get(Item.name) and both get type check and stay refactoring friendly (though with cost of some more typing).