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Regression in DTS generation between TypeScript 5.6 and 5.7 #60506
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
Activity
alxhub commentedon Nov 15, 2024
Note that within the file,
getGroup()'s type is correct. It's only the.d.tsemit that shows the bug.trevorade commentedon Nov 18, 2024
FYI, here's a simpler repro with a few tweaks that can be made to resolve the issue:
https://www.typescriptlang.org/play/?ts=5.7.1-rc#code/CYUwxgNghgTiAEAzArgOzAFwJYHtXwHMYdkAHAHgBV4QAPDEVYAZ3gG8BfAPgAow8MxCMwBc8SgEoxbANoBpeFnwBrEAE8cicQF1pANygRkIMZXnaOHANwAoG6EiwE-VMwzxgUDFADyAIwArAEZpT28xNxglAms7OlIcGHcUdGw8eGRmEABxYjIeCXYbeHgXNw8vX0CAJngAXiKSkrCoMQByNvgoVkjogBp4AHpB+AAlEABbHD1o+AADbvhe1AI5+DhmHAg9EFYsZmZjADpi+FjT4fWQDGQYfCISUh4W-2CJKyGRgHVE5WZTuA3O6EPJPF41d6feAASXQiTgmBsHDsly+WAwAAslPBMfskFgICABpiEBg1KQEJp5pkcqCCms8YYAO5QNSsfgwBEYAabGyXXGsKBgMC7QUQFls+BM37ME403KPApHFpHAxGEC2IA
fix(forms): work around TypeScript 5.7 issue
fix(forms): work around TypeScript 5.7 issue (#58731)
fix(forms): work around TypeScript 5.7 issue (#58731)
weswigham commentedon Dec 4, 2024
This was fixed by #60576 (ref #60573 which dupes this)