Typescript dynamic interface from object values

Question

I am creating args parser from a string. I have interface for defining args names and default values

interface IargsDef {
    name: string;
    default?: string;
}

What I want is for intellisense(make some dynamic interface idk) works with parse result.

For args def

[{
name: "test1"
}, 
{
name: "test2", 
default: "test"
}]

It woult be look like that

{
"test1": "some value",
"test2": "some value or default"
}

But intellisense will not see these properties.

Try this https://catchts.com/tuples#reduce – captain-yossarian from Ukraine May 17 '21 at 11:50 — captain-yossarian from Ukraine, May 17 '21 at 11:50
Nope, it's not helping, or I understand wrongly – Ryner May 17 '21 at 17:41 — Ryner, May 17 '21 at 17:41

score 0 · Accepted Answer · answered May 18 '21 at 10:20

If I've understood what you're looking for correctly, then something like this might do the trick:

interface IArgsDef<Name extends string> {
    name: Name;
    default?: string;
}

const argsDef = {
  test1: { name: "test1" },
  test2: { name: "test2", default: "test" }
}

type ArgsInput<Defs extends Record<string, unknown>> = Defs[keyof Defs] extends IArgsDef<infer _>
  ? Record<keyof Defs, string>
  : never

type ExpectedInput = ArgsInput<typeof argsDef>
// type ExpectedInput = {
    // test1: string;
    // test2: string;
}

I changed the way your args definition is defined from an array to an object in order to make this work though, which I'm not sure is acceptable or not.

Typescript dynamic interface from object values

1 Answers1