src/main/java/fr/iut_fbleau/but3/dev62/mylibrary/book/exception/BookNotFoundException.java

@@ -0,0 +1,11 @@
+package fr.iut_fbleau.but3.dev62.mylibrary.book.exception;
+
+import java.text.MessageFormat;
+
+public class BookNotFoundException extends RuntimeException {
+    public static final String THE_BOOK_WITH_ID_DOES_NOT_EXIST_MESSAGE = "The book with isbn {0} does not exist";
+
+    public BookNotFoundException(String isbn) {
+        super(MessageFormat.format(THE_BOOK_WITH_ID_DOES_NOT_EXIST_MESSAGE, isbn));
+    }
+}

src/test/java/fr/iut_fbleau/but3/dev62/mylibrary/book/exception/BookNotFoundExceptionTest.java

@@ -0,0 +1,48 @@
+package fr.iut_fbleau.but3.dev62.mylibrary.book.exception;
+
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+public class BookNotFoundExceptionTest {
+
+    @Test
+    @DisplayName("Exception message should contain the isbn provided")
+    void testExceptionMessageContainsIsbn() {
+        String isbn = "1234567891012";
+
+        BookNotFoundException exception = new BookNotFoundException(isbn);
+
+        String expectedMessage = String.format("The book with isbn %s does not exist", isbn);
+        assertEquals(expectedMessage, exception.getMessage());
+    }
+
+    @Test
+    @DisplayName("Exception should use the correct constant message format")
+    void testExceptionUsesConstantMessageFormat() {
+        String isbn = "1234567891012";
+
+        BookNotFoundException exception = new BookNotFoundException(isbn);
+
+        String expectedFormatWithPlaceholder = "The book with isbn {0} does not exist";
+        assertEquals(BookNotFoundException.THE_BOOK_WITH_ID_DOES_NOT_EXIST_MESSAGE,
+                expectedFormatWithPlaceholder);
+        assertTrue(exception.getMessage().contains(isbn.toString()));
+    }
+
+    @Test
+    @DisplayName("Exception should be properly thrown and caught")
+    void testExceptionCanBeThrownAndCaught() {
+        String isbn = "1234567891012";
+
+        try {
+            throw new BookNotFoundException(isbn);
+        } catch (BookNotFoundException e) {
+            String expectedMessage = String.format("The book with isbn %s does not exist", isbn);
+            assertEquals(expectedMessage, e.getMessage());
+        }
+    }
+}

src/test/java/fr/iut_fbleau/but3/dev62/mylibrary/book/usecase/BookUseCaseTest.java

@@ -6,6 +6,7 @@ import fr.iut_fbleau.but3.dev62.mylibrary.book.BookInfo;
 import fr.iut_fbleau.but3.dev62.mylibrary.book.BookSalesInfo;
 import fr.iut_fbleau.but3.dev62.mylibrary.book.entity.Book;
 import fr.iut_fbleau.but3.dev62.mylibrary.book.exception.BookNotFoundException;
+import fr.iut_fbleau.but3.dev62.mylibrary.book.exception.BookNotFoundExceptionTest;
 import fr.iut_fbleau.but3.dev62.mylibrary.book.exception.IllegalBookStockException;
 import fr.iut_fbleau.but3.dev62.mylibrary.book.exception.NotValidBookException;
 import fr.iut_fbleau.but3.dev62.mylibrary.book.repository.BookRepository;