part of handler.js

const getAllBookHandler = (request, h) => {
  const { name, reading, finished } = request.query;
  let response;
  let ket;
  if (reading !== undefined || finished !== undefined || name !== undefined) {
    if (reading === '1' || finished === '1') {
      ket = true;
    } else {
      ket = false;
    }
    if (reading) {
      response = h.response({
        status: 'success',
        data: {
          books: books.filter((x) => x.reading === ket).map((book) => ({
            id: book.id,
            name: book.name,
            publisher: book.publisher,
          })),
        },
      });
    }
    if (finished) {
      response = h.response({
        status: 'success',
        data: {
          books: books.filter((x) => x.finished === ket).map((book) => ({
            id: book.id,
            name: book.name,
            publisher: book.publisher,
          })),
        },
      });
    }
    if (name) {
      response = h.response({
        status: 'success',
        data: {
          books: books.filter((x) => x.name.toLowerCase().includes(name.toLowerCase()))
            .map((book) => ({
              id: book.id,
              name: book.name,
              publisher: book.publisher,
            })),
        },
      });
    }
  } else {
    response = h.response({
      status: 'success',
      data: {
        books: books.map((book) => ({
          id: book.id,
          name: book.name,
          publisher: book.publisher,
        })),
      },
    });
  }
  return response;
};