Provide type inference for sub-document operations

type Book = {

  authors: string[];

  sales: [number, number],

}

const result = cb.collection('my_collection').lookupIn<Book>('foo', [

  LookupInSpec.get('authors'), <== 👌

  LookupInSpec.get('sales[3]'), <== Type Error

]);

declare module 'couchbase' {

  class LookupInSpec<T> {

    static get<T = any>(path: DocumentPath<T> | LookupInMacro, options?: { xattr?: boolean; });

  }

  class Collection {

    lookupIn<T = any>(key: string, specs: LookupInSpec<T>[], options?: LookupInOptions, callback?: NodeCallback<LookupInResult>): Promise<LookupInResult>;

  }

}

type TupleIndices<T extends readonly unknown[]> = Exclude<Partial<T>['length'], T['length']> & number;

type ArrayIndices<T extends readonly unknown[]> = number extends T['length']

  ? -1 | (number & {})

  : 0 extends TupleIndices<T> ? TupleIndices<T> | -1 : never;

type AccessibleKey = string | number;

type ArrayAccessor<T extends readonly unknown[], K extends AccessibleKey> = K extends ArrayIndices<T> ? `[${K}]` : never;

type ObjectAccessor<K extends AccessibleKey, IsRoot extends boolean> = IsRoot extends true ? K : `.${K}`;

type Accessor<T, K extends AccessibleKey, IsRoot extends boolean> =

  T extends readonly unknown[] ? ArrayAccessor<T, K> : ObjectAccessor<K, IsRoot>;

export type DocumentPath<T, IsRoot extends boolean = true, K extends keyof T = keyof T> = K extends AccessibleKey

  ? `${Accessor<T, K, IsRoot>}${'' | (

    T[K] extends readonly unknown[]

      ? DocumentPath<T[K], false, ArrayIndices<T[K]>>

      : (T[K] extends object ? DocumentPath<T[K], false> : '')

    )}`

  : never