@payfit/unity-components/dist/esm/hooks/tanstack-form-default-values.d.ts

/**
 * Mirrors a form submit value shape while allowing each nested value to be
 * initialized with `undefined`.
 *
 * TanStack Form `defaultValues` often describe an incomplete form state: a
 * field can start empty even when the validated submit payload requires it.
 * This type keeps the submit schema as the source of truth while making those
 * empty initial field values type-safe.
 */
type DeepAllowUndefined<T> = T extends Array<infer Item> ? Array<DeepAllowUndefined<Item>> | undefined : T extends object ? {
    [K in keyof T]: DeepAllowUndefined<T[K]> | undefined;
} : T | undefined;
/**
 * Makes one path required again after `DeepAllowUndefined` allowed `undefined`
 * throughout the value shape.
 *
 * Paths are expressed as tuples of object keys. Use `number` to target every
 * item in an array, for example `['answers', number, 'questionId']`.
 */
type KeepRequiredAtPath<T, Path extends readonly unknown[]> = Path extends [] ? Exclude<T, undefined> : T extends Array<infer Item> ? Path extends [number, ...infer Rest extends readonly unknown[]] ? Array<KeepRequiredAtPath<Item, Rest>> : T : Path extends [
    infer Key extends keyof T,
    ...infer Rest extends readonly unknown[]
] ? Omit<T, Key> & {
    [K in Key]-?: KeepRequiredAtPath<Exclude<T[Key], undefined>, Rest>;
} : T;
/**
 * Applies `KeepRequiredAtPath` to several paths.
 *
 * This is useful when some containers or technical identifiers must always be
 * present in `defaultValues`, while regular user-input fields can still start
 * as `undefined`.
 */
type KeepRequiredAtPaths<T, Paths extends ReadonlyArray<readonly unknown[]>> = Paths extends readonly [
    infer Path extends readonly unknown[],
    ...infer Rest extends ReadonlyArray<readonly unknown[]>
] ? KeepRequiredAtPaths<KeepRequiredAtPath<T, Path>, Rest> : T;
/**
 * Helper type for TanStack Form `defaultValues`.
 *
 * It starts from the final submit values, allows `undefined` throughout the
 * default form state, then re-requires the paths listed in `RequiredPaths`.
 *
 * We created it to avoid maintaining a separate default-values type or using
 * unsafe casts when default values are intentionally less complete than the
 * validated submit payload.
 */
export type TanstackFormDefaultValues<SubmitValues, RequiredPaths extends ReadonlyArray<readonly unknown[]> = []> = KeepRequiredAtPaths<DeepAllowUndefined<SubmitValues>, RequiredPaths>;
/**
 * Runtime no-op used to type-check TanStack Form default values.
 *
 * The function returns the provided value unchanged. Its purpose is to make
 * object literals satisfy `TanstackFormDefaultValues` at compile time while
 * keeping call sites compact.
 */
export declare function tanstackFormDefaultValues<SubmitValues, RequiredPaths extends ReadonlyArray<readonly unknown[]> = []>(value: TanstackFormDefaultValues<SubmitValues, RequiredPaths>): KeepRequiredAtPaths<DeepAllowUndefined<SubmitValues>, RequiredPaths>;
export {};