Idea for type to generically describe a single key-value object from a multi key value object

[renewooller]

Given an object structure like:

interface A {
    AA : string
    BB : number
}

derive:

type C = {AA : string } | { BB : number}

This is how:

type Unionify<T> = {[K in keyof T]: Pick<T, K>}[keyof T];

type C = Unionify<A>

I'm not sure if it should be called Unionify or OneOf. Any idea on naming or other feedback appreciated.

[pelotom]

The name Unionize has some precedent:

• Using const string enum as object key produces an indexed type microsoft/TypeScript#16687
• Incorrect union type inferred microsoft/TypeScript#17930

[renewooller]

Maybe OneOf is better then just to more clearly separate it from Unionize?

[pelotom]

Isn't it the same thing as Unionize? Why do we want to separate it?

[renewooller]

Unionize looks like it also does Key(Tag)Valueification in the same step. That is, rather than {AA : string } | { BB : number} it does {tag : "AA", value : string } | { tag : "BB", value : number}. I may be reading it wrong though.