--description--

Objective: Fulfill the user stories below and get all the tests to pass to complete the lab.

User Stories:

You should have an array of objects named books where each object in the array should have a string title, another string authorName, and a number releaseYear.
Your books array should have a minimum of three objects.
You should have a callback function named sortByYear that accepts two books as parameter for sorting the array.
The sortByYear function should return -1 if the releaseYear of the first book is smaller than that of the second book.
The sortByYear function should return 1 if the releaseYear of the first book is bigger than that of the second book.
The sortByYear function should return 0 if both releaseYear values are equal.
You should filter out books written after a certain year such as 1950 from the books array and save the filtered array in a new array named filteredBooks.
You should sort the books in the filteredBooks array according to their releaseYear in ascending order. You learned in a prior lesson that the sort() method will sort the array in place. This means the filteredBooks array will be mutated.

--hints--

You should have a function sortByYear in your code.

assert.isFunction(sortByYear);

Your sortByYear function should take two parameters.

assert.lengthOf(sortByYear, 2);

Your sortByYear function should return -1 if the releaseYear of book1 object is smaller than that of the book2 object, 1 if the releaseYear of book1 object is larger than that of the book2 object, and 0 in all other scenarios.

assert.equal(sortByYear({releaseYear: 1913}, {releaseYear: 1925}), -1);
assert.equal(sortByYear({releaseYear: 1925}, {releaseYear: 1913}), 1);
assert.equal(sortByYear({releaseYear: 1925}, {releaseYear: 1925}), 0);

You should have an array books in your code.

assert.isArray(books)

Your books array should have at least three book objects.

assert.isAtLeast(books.length, 3)

Your books array should contain objects each with a string title, another string authorName, and a number releaseYear.


books.forEach((book) => {
  assert.isObject(book);
  assert.sameMembers(Object.keys(book), ["title", "authorName", "releaseYear"]);
  assert.isString(book.title);
  assert.isNotEmpty(book.title);
  assert.isString(book.authorName);
  assert.isNotEmpty(book.authorName);
  assert.isNumber(book.releaseYear);
})

You should have an array filteredBooks in your code.

assert.isArray(filteredBooks)

The filteredBooks array should have some of the books filtered out from the books array and not be empty.

assert.isBelow(filteredBooks.length, books.length)
assert.isNotEmpty(filteredBooks)

The filteredBooks array should only contain books from the original books array.

filteredBooks.forEach(book => {
  assert.isTrue(
    books.some(original => 
      original.title === book.title &&
      original.authorName === book.authorName &&
      original.releaseYear === book.releaseYear
    )
  );
});

The filteredBooks array should include only books released on or before a specified year.

const maxYear = Math.max(...filteredBooks.map(book => book.releaseYear));
const removedYears = books.filter(book => !filteredBooks.includes(book)).map(book => book.releaseYear);
assert.isTrue(removedYears.every(year => year > maxYear));

You should call the sort higher order function by passing the sortByYear callback function on the filteredBooks array.

assert.match(__helpers.removeJSComments(code), /\s*filteredBooks\s*\.\s*sort\s*\(\s*sortByYear\s*\)/);

--seed--

--seed-contents--

--solutions--

function sortByYear(book1, book2) {
  if (book1.releaseYear < book2.releaseYear) {
    return -1;
  }

  if (book1.releaseYear > book2.releaseYear) {
    return 1;
  }

  return 0;
}

const books = [
  {
    title: "The Great Gatsby",
    authorName: "F. Scott Fitzgerald",
    releaseYear: 1925,
  },
  {
    title: "In Search of Lost Time",
    authorName: "Marcel Proust",
    releaseYear: 1913,
  },
  {
    title: "Ulysses",
    authorName: "James Joyce",
    releaseYear: 1922,
  },
  {
    title: "One Hundred Years of Solitude",
    authorName: "Gabriel García Márquez",
    releaseYear: 1967,
  },
  {
    title: "The Catcher in the Rye",
    authorName: "J. D. Salinger",
    releaseYear: 1951,
  },
];

let filteredBooks = books.filter((book) => book.releaseYear < 1950);

filteredBooks.sort(sortByYear);

console.log("Books Written Before 1950 (sorted according to release year)");
filteredBooks.forEach((book) => {
  console.log(`${book.title} by ${book.authorName} (${book.releaseYear})`);
});

Build a Book Organizer

--description--

--hints--

--seed--

--seed-contents--

--solutions--