finish exercise

school-library/src/main/java/com/redhat/training/Library.java

@@ -21,6 +21,7 @@ public Library(Inventory inventory) {
     }
 
     public Book checkOut(String studentId, String isbn) throws BookNotAvailableException {
+
         if (!inventory.isBookAvailable(isbn)) {
             throw new BookNotAvailableException(isbn);
         }

school-library/src/test/java/com/redhat/training/BookStatsTest.java

@@ -22,6 +22,13 @@ public void countingWordsOfEmptyBookReturnsZero() {
 
     @Test
     public void countingWordsReturnsNumberOfWordsInBook() {
-        assertEquals(0, 1); // Replace this line with the actual test code...
+        // Given
+        Book book = new Book("someISBN", "this is the content");
+
+        // When
+        double wordCount = BookStats.countWords(book);
+
+        // Then
+        assertEquals(4, wordCount);
     }
 }

school-library/src/test/java/com/redhat/training/LibraryTest.java

@@ -24,4 +24,40 @@ public void setUp() {
     }
 
     // Add tests here...
+    @Test
+    public void checkingOutDecreasesNumberOfBookCopiesFromInventory()
+        throws BookNotAvailableException {
+        // Given
+        inventory.add(new Book("book1"));
+        inventory.add(new Book("book1"));
+
+        // When
+        library.checkOut("someStudentId", "book1");
+
+        // Then
+        assertEquals(1, inventory.countCopies("book1"));
+    }
+
+    @Test
+    public void checkingOutUnavailableBookThrowsException()
+            throws BookNotAvailableException {
+        // Given
+        inventory.add(new Book("book1"));
+        inventory.add(new Book("book1"));
+
+        library.checkOut("student1", "book1");
+        library.checkOut("student2", "book1");
+
+        // When
+        final BookNotAvailableException exception = assertThrows(
+            BookNotAvailableException.class,
+            () -> {
+                library.checkOut("student3", "book1");
+            }
+        );
+
+        // Then
+        assertTrue(exception.getMessage().matches("Book book1 is not available"));
+    } 
+
 }

school-library/src/test/java/com/redhat/training/LibraryWithMockedInventoryTest.java

@@ -24,4 +24,35 @@ public void setUp() {
     }
 
     // Add tests here...
+    @Test
+    public void checkingOutWithdrawsFromInventoryWhenBookIsAvailable()
+            throws BookNotAvailableException {
+        // Given
+        when(inventory.isBookAvailable("book1")).thenReturn(true);
+
+        // When
+        library.checkOut("student1", "book1");
+
+        // Then
+        verify(inventory).withdraw("book1");
+    }
+
+    @Test
+    public void checkingOutDoesNotWithdrawFromInventoryWhenBookIsUnavailable()
+            throws BookNotAvailableException {
+        // Given
+        when(inventory.isBookAvailable("book1")).thenReturn(false);
+
+        // When
+        try {
+            library.checkOut("student1", "book1");
+        } catch(BookNotAvailableException e) {}
+
+        // Then
+        verify(inventory, times(0)).withdraw("book1");                          
+
+    }
+
+
+
 }