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// @strict: true
// @lib: esnext
// @noEmit: true
// repro from https://github.com/microsoft/TypeScript/issues/43877
type UnionToIntersection<U> = (
U extends any ? (k: U) => unknown : never
) extends (k: infer I) => unknown
? I
: never;
interface ClassSpec {
public?: object;
private?: object;
publicExtends?: Record<string, ClassSpec>;
privateExtends?: Record<string, ClassSpec>;
}
type MaybeMergePrivateSuperSpec<T> = T extends Record<string, ClassSpec>
? MergePrivateSuperSpec<T>
: {};
type MaybeMergePrivateSpecs<T extends ClassSpec, U> = U extends ClassSpec
? MergePrivateSpecs<U, T>
: T;
type MergePrivateSpecs<T extends ClassSpec, U extends ClassSpec> = {
public: T["public"] & U["public"];
private: T["private"] & U["private"];
};
type MergePrivateSuperSpec<T extends Record<string, ClassSpec>> =
UnionToIntersection<
{
[P in keyof T]: SimplifyPrivateSpec<T[P]>;
}[keyof T]
>;
export type SimplifyPrivateSpec<T extends ClassSpec> = MaybeMergePrivateSpecs<
MaybeMergePrivateSpecs<T, MaybeMergePrivateSuperSpec<T["publicExtends"]>>,
MaybeMergePrivateSuperSpec<T["privateExtends"]>
>;
// repro from https://github.com/microsoft/TypeScript/issues/43877#issuecomment-866146516
type Converted<T> = {
[P in keyof T]: null extends T[P] ? T[P] : T[P];
};
type DefaultsDeep<T, U extends T> = {
[P in keyof T]-?: U[P] extends T[P]
? null extends U[P]
? Converted<DefaultsDeep<T[P], NonNullable<U[P]>>>
: T[P]
: T[P];
};
interface _Array<T> {
find<S extends T>(predicate: (value: T) => boolean): void;
}
const z: _Array<DefaultsDeep<{}, {}>> = [];
z.find((_) => true);
|
