A Complex Union Type

How to get this union type:

type MyType = "x:a" | "x:b" | "x:c" | "y:d" | "y:f" | "y:g";

type MyType = "x:a" | "x:b" | "x:c" | "y:d" | "y:f" | "y:g";

From this object:

const obj = {
  x: [
    { value: 'a', checked: false },
    { value: 'b', checked: false },
    { value: 'c', checked: false },
  ],
  y: [
    { value: 'd', checked: false },
    { value: 'f', checked: false },
    { value: 'g', checked: false },
  ],
} as const;

const obj = {
  x: [
    { value: 'a', checked: false },
    { value: 'b', checked: false },
    { value: 'c', checked: false },
  ],
  y: [
    { value: 'd', checked: false },
    { value: 'f', checked: false },
    { value: 'g', checked: false },
  ],
} as const;

This is the best I could do:

type ObjKey = keyof typeof obj;
type MyType = `${ObjKey}:${(typeof obj)[ObjKey][number]['value']}`;

type ObjKey = keyof typeof obj;
type MyType = `${ObjKey}:${(typeof obj)[ObjKey][number]['value']}`;

But it will combine both x and y with a..g

2 Replies

Igal•2y ago

Hey 👋 Something like this https://www.typescriptlang.org/play?#code/MYewdgzgLgBCBGArGBeGBvAUDGAPAXDANrY4YwBuAhgDYCuApoQORXMA0MwAFg8ANYMAJoQBmtCAxgBfdqRzpKtRi3gcuvAcLESps+eWr0mMZsHU8+gkTHE1JMuTgC6TmAE9CJMoeUnmQhaa1jr2em4KSsYsokFW2ra6jgaKRiqmAOZxWjZ2DvouctIwVBBc4NAA3JiYUO4ADlIAklAMALYAPABqMAy4rWBCZdAATgCWYBmoMKMTGQB806l+hF2VGvE28CAgNAxUYDLVtQ1SAMIgbdsQHQDyvf0Mg2UASnwgI0Ids5OcI-tCcA0dwwFrtIjOeaLNCkRREADSMAmMEE7hAohg9wAZDMoONJs5CAADAAk6Hh0nwZNuCOcRDAdCuDBGdOYaQYzGc0iJMiIqPRmJgOJ+GWcxzqjRgbwgdBosDQFyuIBuEoYAoQiHmQA

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ahkhanjaniOP•2y ago

OH MY GOD god bless you

Gaming

Programming

A Complex Union Type