Type that converts all strings to function that returns string

I have an object like

{
  foo: 'hey'
  bar: {
    bar1: 'sup'
    bar2: {
      bar3: 'love you'
    }
  }
}

{
  foo: 'hey'
  bar: {
    bar1: 'sup'
    bar2: {
      bar3: 'love you'
    }
  }
}

I want to create a type that converts all the strings to functions that return strings. For example, typeof bar.bar2.bar3 = () => "love you" I have no idea how to do this lol

17 Replies

Froxx•3y ago

I guess what you want to create is a function, not a type. So you would need a recursive function that does following things: 1. check if passed parameter is a primitive (string, or maybe number, bool, ...), if so return "() => parameter" 2. if param is array, map through it and call itself with each item as the new parameter 3. if param is object, map do the same for all objects props ( Object.keys(obj) )

benten•3y ago

I'm actually trying to lie to the compiler about the type It's not actually a function that returns a string, but I want tsc (and autocomplete) to think it is

barry•3y ago

type Stringify<E> = { [K in keyof E]: () => E[K] };

type Stringify<E> = { [K in keyof E]: () => E[K] };

something like this im not sure, not a wizard

Froxx•3y ago

Oh alright. Then I'm out as well 😅 I would generally recommend using the Record<key, value> syntax instead of { [key]: value }. A bit more clear imo

benten•3y ago

This will cast bar as a string when it should be an object I tried Omit<Record<string, string>, keyof typeof myObject> but it didn't work The part I'm stuck on is only casting the strings, not the objects

barry•3y ago

const E = {
  foo: "one",
  bar: {
    one: "bar",
    two: "baz",
  }
} as const;

type barrystype<T> = {
  [K in keyof T]: T[K] extends string ? () => T[K] : barrystype<T[K]>
}

const E = {
  foo: "one",
  bar: {
    one: "bar",
    two: "baz",
  }
} as const;

type barrystype<T> = {
  [K in keyof T]: T[K] extends string ? () => T[K] : barrystype<T[K]>
}

maybe that will work as const is important

benten•3y ago

sadly not

barry•3y ago

it should

benten•3y ago

global and home are objects

barry•3y ago

works for me

barry•3y ago

oh no kinda

benten•3y ago

wait it does work vscode shows it as strings when you hover, but it doesn't complain when you invoke it

benten•3y ago

benten•3y ago

thanks barry you a g

barry•3y ago

dont thank me thank some dude on typescript discord lol InfectiousFight#0245

Unknown User•3y ago

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Type that converts all strings to function that returns string