getBookById.ts

interface BookDetailsViewModel {
  title: string
  is_available: boolean
}

export function getBookById(dependencies: Dependencies) {
  return async (req: Request, res: Response) => {
    try {
      const result = await dependencies
        .bookInformation(req.params.id)

      res.json(_mapToBookDetailsViewModel(result))
    } catch (e) {
      res.status(404).json(e.toString())
    }
  }
}

function _mapToBookDetailsViewModel(result: BookDetails): BookDetailsViewModel {
  return {
    title: result.title,
    is_available: result.isAvailable
  }
}