FindAll.java

//Scala
assert(books.filter((book: Book) => book.author == "Bob") == List(new Book("Clean Code", "Bob", 100), new Book("Extreme Programming", "Bob", 200)))
//Or
assert(books.filter(book => book.author == "Bob") == List(new Book("Clean Code", "Bob", 100), new Book("Extreme Programming", "Bob", 200)))
//Or
assert(books.filter(_.author == "Bob") == List(new Book("Clean Code", "Bob", 100), new Book("Extreme Programming", "Bob", 200)))

  
//Java
assertThat(
          books.stream()
                  .filter(book -> book.getAuthor().equals("Bob"))
                  .collect(Collectors.toList())
          , is(Arrays.asList(
                  new Book("Clean Code", "Bob", 100),
                  new Book("Extreme Programming", "Bob", 200)
          )));

//Or

  assertThat(books.stream()
                  .filter((Book book) -> book.getAuthor().equals("Bob"))
                  .collect(Collectors.toList()),
          is(Arrays.asList(
                  new Book("Clean Code", "Bob", 100),
                  new Book("Extreme Programming", "Bob", 200)
          )));
       
//Groovy
assert books.findAll { Book book -> book.author == "Bob" } == [new Book("Clean Code", "Bob", 100), new Book("Extreme Programming", "Bob", 200)]
//Or
assert books.findAll { book -> book.author == "Bob" } == [new Book("Clean Code", "Bob", 100), new Book("Extreme Programming", "Bob", 200)]
//Or
assert books.findAll { it.author == "Bob" } == [new Book("Clean Code", "Bob", 100), new Book("Extreme Programming", "Bob", 200)]