[JITERA] Implement PATCH /books/:id Endpoint for Partial Book Updates

Created by: chi-jitera

Overview

This pull request introduces a new endpoint for partially updating book resources using the PATCH method. The implementation allows clients to update only the fields they provide, rather than requiring a complete replacement of the book resource.

Changes

1. Update /routes/bookRoutes.js

   • Added a new route for PATCH requests to handle partial updates for books.

   router.patch('/books/:id', bookController.patchBook);

2. Update /controllers/bookController.js

   • Implemented the patchBook controller method to handle incoming PATCH requests. This method calls the corresponding service method to perform the update.

   exports.patchBook = async (req, res) => {
       try {
           const updatedBook = await bookService.patchBook(req.params.id, req.body);
           res.json(updatedBook);
       } catch (error) {
           res.status(400).json({ error: error.message });
       }
   };

3. Update /services/bookService.js

   • Added the patchBook service method to handle the logic for partial updates. This method validates the publishedYear field only if it is present in the request body and uses Mongoose's $set operator to update the specified fields.

   exports.patchBook = async (bookId, patchData) => {
       if (patchData.hasOwnProperty('publishedYear')) {
           validateBookData(patchData);
       }
       const book = await Book.findByIdAndUpdate(bookId, { $set: patchData }, { new: true, runValidators: true });
       if (!book) throw new Error('Book not found');
       return book;
   };

This implementation enhances the API by allowing more flexible updates to book resources, improving usability for clients that may only need to change specific fields.