checkBookNode example

// Create two books.     $book_1_nodes = $this->createBook(['moderation_state[0][state]' => 'published']);
    $book_1 = $this->book;

    $this->createBook(['moderation_state[0][state]' => 'published']);
    $book_2 = $this->book;

    $this->drupalLogin($this->bookAuthor);

    // Check that book pages display along with the correct outlines.     $this->book = $book_1;
    $this->checkBookNode($book_1, [$book_1_nodes[0], $book_1_nodes[3], $book_1_nodes[4]], FALSE, FALSE, $book_1_nodes[0], []);
    $this->checkBookNode($book_1_nodes[0], [$book_1_nodes[1], $book_1_nodes[2]], $book_1, $book_1, $book_1_nodes[1], [$book_1]);

    // Create a new book page without actually attaching it to a book and create     // a draft.     $edit = [
      'title[0][value]' => $this->randomString(),
      'moderation_state[0][state]' => 'published',
    ];
    $this->drupalGet('node/add/book');
    $this->submitForm($edit, 'Save');
    $node = $this->drupalGetNodeByTitle($edit['title[0][value]']);
    

  public function testBook() {
    // Create new book.     $nodes = $this->createBook();
    $book = $this->book;

    $this->drupalLogin($this->webUser);

    // Check that book pages display along with the correct outlines and     // previous/next links.     $this->checkBookNode($book, [$nodes[0], $nodes[3], $nodes[4]], FALSE, FALSE, $nodes[0], []);
    $this->checkBookNode($nodes[0], [$nodes[1], $nodes[2]], $book, $book, $nodes[1], [$book]);
    $this->checkBookNode($nodes[1], NULL, $nodes[0], $nodes[0], $nodes[2], [$book, $nodes[0]]);
    $this->checkBookNode($nodes[2], NULL, $nodes[1], $nodes[0], $nodes[3], [$book, $nodes[0]]);
    $this->checkBookNode($nodes[3], NULL, $nodes[2], $book, $nodes[4], [$book]);
    $this->checkBookNode($nodes[4], NULL, $nodes[3], $book, FALSE, [$book]);

    $this->drupalLogout();
    $this->drupalLogin($this->bookAuthor);

    // Check the presence of expected cache tags.     $this->drupalGet('node/add/book');