Do not delete all the books on the indexer

src/main/java/ink/kindler/metasearch/integration/scheduler/StandardEbooksIndexer.java

@@ -27,7 +27,7 @@ public StandardEbooksIndexer(StandardEbooksIntegration standardEbooksIntegration
   @SchedulerLock(name = "StandardEbooksIndexer", lockAtLeastFor = "10m", lockAtMostFor = "30m")
   public void indexEbooks() {
     logger.info("Started StandardEbooks indexer");
-    bookService.deleteAll();
+    bookService.deleteAll(Provider.STANDARD_EBOOKS);
     var ebooks = standardEbooksIntegration.retrieveAllEbooksFromFeed().parallelStream().map(this::convertToBook).toList();
     bookService.saveBooks(ebooks);
     logger.info("Finished StandardEbooks indexer. {} ebooks upserted", ebooks.size());

src/main/java/ink/kindler/metasearch/persistent/repository/BookRepository.java

@@ -25,4 +25,6 @@ OR LOWER(b.title) LIKE LOWER(CONCAT('%', :query, '%')))
         ORDER BY b.author ASC, b.title ASC
       """)
   List<BookOverview> searchBooks(@Param("provider") Provider provider, @Param("query") String query, Pageable pageable);
+
+  void deleteAllByProvider(Provider provider);
 }

src/main/java/ink/kindler/metasearch/service/BookService.java

@@ -16,5 +16,5 @@ public interface BookService {
 
   Optional<Book> getBookById(Long id);
 
-  void deleteAll();
+  void deleteAll(Provider provider);
 }

src/main/java/ink/kindler/metasearch/service/impl/DefaultBookService.java

@@ -40,7 +40,7 @@ public Optional<Book> getBookById(Long id) {
   }
 
   @Override
-  public void deleteAll() {
-    bookRepository.deleteAll();;
+  public void deleteAll(Provider provider) {
+    bookRepository.deleteAllByProvider(provider);
   }
 }

src/test/java/ink/kindler/metasearch/integration/scheduler/StandardEbooksIndexerTest.java

@@ -2,6 +2,7 @@
 
 import ink.kindler.metasearch.integration.service.StandardEbooksIntegration;
 import ink.kindler.metasearch.integration.service.model.StandardEbooksBook;
+import ink.kindler.metasearch.persistent.entity.Provider;
 import ink.kindler.metasearch.service.BookService;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.ExtendWith;
@@ -35,7 +36,7 @@ void shouldIndexEbooksOfStandardEbooksLibrary() {
     standardEbooksIndexer.indexEbooks();
 
     verify(bookService).saveBooks(anyList());
-    verify(bookService).deleteAll();
+    verify(bookService).deleteAll(Provider.STANDARD_EBOOKS);
   }
 
   private List<StandardEbooksBook> stubStandardEbooksBooks() {

src/test/java/ink/kindler/metasearch/persistent/repository/BookRepositoryIntegrationTest.java

@@ -52,6 +52,23 @@ void shouldFindBooksByProviderAndAuthorOrTitleLike() {
     assertThat(foundBooks.get(2).getAuthor()).isEqualTo("Mark Zuckerberg");
   }
 
+  @Test
+  void shouldDeleteAllEbooksByProvider() {
+    var books = List.of(
+        stubBook( "The Adventures of Tom Sawyer", "Mark Twain", Provider.STANDARD_EBOOKS),
+        stubBook("Adventures of Huckleberry Finn", "Mark Twain", Provider.GUTENBERG),
+        stubBook("Mark Zuckerberg", "Mark Zuckerberg", Provider.STANDARD_EBOOKS)
+    );
+
+    bookRepository.saveAll(books);
+    bookRepository.deleteAllByProvider(Provider.STANDARD_EBOOKS);
+
+    var availableBooks = bookRepository.findAll();
+
+    assertThat(availableBooks).size().isEqualTo(1);
+    assertThat(availableBooks.getFirst().getTitle()).isEqualTo("Adventures of Huckleberry Finn");
+  }
+
   private Book stubBook(String title, String author, Provider bookProvider) {
     var book = new Book();
     book.setTitle(title);

src/test/java/ink/kindler/metasearch/service/impl/DefaultBookServiceTest.java

@@ -69,9 +69,9 @@ void shouldFindBookById() {
 
   @Test
   void shouldDeleteAllBooks() {
-    bookService.deleteAll();
+    bookService.deleteAll(Provider.STANDARD_EBOOKS);
 
-    verify(bookRepository).deleteAll();
+    verify(bookRepository).deleteAllByProvider(Provider.STANDARD_EBOOKS);
   }
 
 }