Narrowed union from multiple generic properties

[wet phoenix]

The type of test is Test<string>, I am trying to get the generic value to be Test<'test1' | 'test2' | 'test3' | 'test4'>.

The example is just the minimal version I could provide, in my real use case the object "values" are classes with generics themselves, and I need to create one generic type out of all of the classes inside a parent class if that makes easier to understand.

Here is a more detailed playground link with classes:

[tropic geode]

lenovouser#1984

Playground Link

Preview:```ts
class Child<Value extends string> {
public value: Value;

public constructor({ value }: { value: Value }) {
    this.value = value;
}

}

class Parent<Keys extends readonly string[], const Values extends string> {
public keys: Keys;
public holder: { [Key in Keys[number]]: Child<Values> };

public constructor({ keys, holder }: { keys: Keys, holder: { [Key in Keys[number]]: Child<Values> } }) {
    this.keys = keys;
    this.holder = holder;
}

}

const test = new Parent({
...```

[wet phoenix]

The type of test is:

 Parent<readonly ["key1", "key2", "key3", "key4"], string>

When I would like it to be:

Parent<readonly ["key1", "key2", "key3", "key4"], 'value1' | 'value2' | 'value3' | 'value4'>

[minor kindle]

playground link is broken

[wet phoenix]

Really? Works for me

Will create a new one, sec.

@minor kindle does this work: https://www.typescriptlang.org/play?#code/MYGwhgzhAEDCAWBLEATAPANTCArgU2jwA8AXPAOxRghICdFyBzAPmgG8Aoab6ABxwBGIRMGgA3bPgBc0LLjwBuDlx78hI6MAD25GrRzASW2gAo24yQQC+M8xPky5+aFYCU7FTx4kkEAHT2zgC8FvJKXlYckRygkDAACmC0FCRoANJ4AJ4wxGSUMMlgKDogmdB6DIwA2gC6ADSaOjSyljmkFFTldJWsnF5qwqIA1lkQMhnZ4aqCg9DwWqh4tLbQVRPQDNATEFXkOAC2Aks1NTIIyOhOeBCsVkqefDMa2rp0Bkam5iPZDfOLtC4Vt8xltRr8Figlis1lkNuRQdldgcjrQTmckKhMK1bi53H0vN5fH5gdAQsCpgToD5EP4-pCASE6UsKS4osoXs0yM0QuQ8AB3aCJZLkEhmB7AmRVADk3wAjFKGjKsgAmBXQJWZADMao1ABYpTVoJBGq86g8mcsPJTuBr5TJeQLzqgzKFpOrAnh5bizdb1d9Vfb+XAMSgXR6ZFKParvQ8vBrtYHHSGw5YIx7tTHfXqpYngxcUw53ZZ9ZmeJE3EogA

[tropic geode]

@wet phoenix Here's a shortened URL of your playground link! You can remove the full link from your message.

lenovouser#1984

Playground Link

Preview:```ts
class Child<Value extends string> {
public value: Value;

public constructor({ value }: { value: Value }) {
    this.value = value;
}

}

class Parent<Keys extends readonly string[], const Values extends string> {
public keys: Keys;
public holder: { [Key in Keys[number]]: Child<Values> };
...```

You can choose specific lines to embed by selecting them before copying the link.

[tropic geode]

Jakob#8686

Playground Link

Preview:```ts
class Child<Value extends string> {
public value: Value;

public constructor({ value }: { value: Value }) {
    this.value = value;
}

}

class Parent<Keys extends readonly string[], Key extends Keys[number], const Values extends string> {
public keys: Keys;
...```

You can choose specific lines to embed by selecting them before copying the link.

[polar pecan]

works but adds another generic param, maybe theres another way

[wet phoenix]

@polar pecan that works, thank you so much!

Shall I close this or keep it open for a possible solution without a new generic?