Closed
Description
🔎 Search Terms
.d.ts generation, TypeScript 5.7
🕗 Version & Regression Information
- This changed between versions 5.6.3 and 5.7.1-rc
⏯ Playground Link
Note: look at the ".D.TS" tab in the playground
💻 Code
export class FormControl<T> {
value!: T;
}
export class FormGroup<T> {
controls!: T;
}
class FormBuilder {
group<T extends {}>(
controls: T,
): FormGroup<{[K in keyof T]: FormControl<T[K]>}> {
return null!;
}
}
const fb = new FormBuilder();
export function getGroup() {
return fb.group({
data: [] as string[] | null,
});
}🙁 Actual behavior
Given the code above, TypeScript 5.7 produces a .d.ts file that looks like this:
export declare function getGroup(fb: FormBuilder): FormGroup<{
data: string[] | null; // <----- Incorrect
}>;
🙂 Expected behavior
It should produce something like this:
export declare function getGroup(fb: FormBuilder): FormGroup<{
data: FormControl<string[] | null>;
}>;
Additional information about the issue
Source code of Angular's FormBuilder: https://github.com/angular/angular/blob/main/packages/forms/src/form_builder.ts