Adjust mock expectations for QuerydslDataFetcher

See gh-71

Author: rstoyanchev

spring-graphql/src/test/java/org/springframework/graphql/data/QuerydslDataFetcherTests.java

@@ -73,7 +73,7 @@ void shouldFetchMultipleItems() {
 		MockRepository mockRepository = mock(MockRepository.class);
 		Book book1 = new Book(42L, "Hitchhiker's Guide to the Galaxy", "Douglas Adams");
 		Book book2 = new Book(53L, "Breaking Bad", "Heisenberg");
-		when(mockRepository.findAll((Predicate) null)).thenReturn(Arrays.asList(book1, book2));
+		when(mockRepository.findAll(any(Predicate.class))).thenReturn(Arrays.asList(book1, book2));
 
 		WebGraphQlHandler handler = initWebGraphQlHandler(builder -> builder
 				.dataFetcher("books", QuerydslDataFetcher.builder(mockRepository).many()));
@@ -169,7 +169,7 @@ void shouldReactivelyFetchMultipleItems() {
 		ReactiveMockRepository mockRepository = mock(ReactiveMockRepository.class);
 		Book book1 = new Book(42L, "Hitchhiker's Guide to the Galaxy", "Douglas Adams");
 		Book book2 = new Book(53L, "Breaking Bad", "Heisenberg");
-		when(mockRepository.findAll((Predicate) null)).thenReturn(Flux.just(book1, book2));
+		when(mockRepository.findAll((Predicate) any())).thenReturn(Flux.just(book1, book2));
 
 		WebGraphQlHandler handler = initWebGraphQlHandler(builder -> builder
 				.dataFetcher("books", QuerydslDataFetcher.builder(mockRepository).many()));