Computed property invalid in type declaration emitted in d.ts file

🔎 Search Terms

computed property unique symbols declaration emit

🕗 Version & Regression Information

• This is the behavior in every version I tried

⏯ Playground Link

https://www.typescriptlang.org/play/?ts=5.7.2#code/MYGwhgzhAEAq0G8BQ1XQgFzBglsaATgKZgAmA9gHYgCe0A2gEQaMC6AXNAK6U4COXIuhoBbAEbkQAbiQBfJCCIZoAD07I0DWExasO0Sl3FECM2TMXK6AXkQo09bczb6AjHKRA

💻 Code

class T {
    static readonly ["t"]: unique symbol;
}
let x: {
    [T["t"]]: number;
};
let y = {
    [T["t"]]: 1
}

🙁 Actual behavior

The type of x has an error saying: A computed property name in a type literal must refer to an expression whose type is a literal type or a 'unique symbol'

The type of y is emitted in declaration files just like the type of x and causes an error in the d.ts file

🙂 Expected behavior

The type of x should be valid. If we use a non-computed property name, the type would be valid (let x: { [T.t]: number; }, Playground Link). Declaration emit should not emit invalid code.

Additional information about the issue

Probably fixed by #60052 since the limitation on computed property names in types goes away.

Start with the provided TypeScript Playground reproduction and inspect the computed-property handling for type literals and declaration emit. Compare the behavior with the limitation discussed in issue #60052; done means the type is accepted and declaration emit no longer produces an invalid .d.ts file.