Augment flag keys in ".flags" type definition

[voxpelli]

Unfortunately this doesn't seems doable yet, but it is something that is discussed here it seems: microsoft/TypeScript#12754

So currently .flags['foo-bar'] will have the same type as .unnormalizedFlags['foo-bar'], whereas only the latter should have that, the former should have it's key augmented into .flags.fooBar or at least have the errenous foo-bar key removed.

I believe none of that is possible right now, but wanted to open an issue and track that it would be preferable, as that can then eg. tie into the discussions within TypeScript itself.

[voxpelli]

Correcting myself: .unnormalizedFlags shouldn't have kebabcased keys either.

[voxpelli]

Closing this as this somewhat duplicates: #165 (comment)

Just a note, it may soon be possible to do something about this as the TypeScript 4.1 beta supports:

type Getters<T> = {
    [K in keyof T as `get${capitalize K}`]: () => T[K]
};

interface Person {
    name: string;
    age: number;
    location: string;
}

type LazyPerson = Getters<Person>;

If there would be a Split<"foo-bar", "-"> (they are switching to having capitalize K be Capitalize<K> in microsoft/TypeScript#40580) then maybe one could rewrite it as:

type CamelCase<K extends string> = `${Split<K, "-">[0]}${Capitalize<Split<K, "-">[1] | "">}

type CamelCasedProps<T> = {
    [K in keyof T as CamelCase<K>]: () => T[K]
};

interface KebabCased {
    "foo-bar": string;
    foo: number;
}

type CamelCased = CamelCasedProps<KebabCased>;

[voxpelli]

Actually, it is already possible: microsoft/TypeScript#40710 (comment)

[sindresorhus]

@voxpelli Should we reopen this?

[voxpelli]

@sindresorhus Yeah, lets do it.

So, this would rely on sindresorhus/type-fest#134 I'm thinking.

• it would require TypeScript 4.1, which I'm not really sure when/how one can reliably require? At least would have to wait for eg. VS Code to have shipped with it (and of course for TS 4.1 to itself have shipped)

Unless of course one can publish these new types in a way that works with older TS versions, but I doubt it

[sindresorhus]

it would require TypeScript 4.1, which I'm not really sure when/how one can reliably require? At least would have to wait for eg. VS Code to have shipped with it (and of course for TS 4.1 to itself have shipped)

I'm ok with requiring TS 4.1 a couple of months after it has shipped. The benefits are worth it.