public async Task ItShallReturnBooksContainingTitle() { // Given A.CallTo(() => nameGenerator.GenerateBookTitleAsync()).Returns(new ValueTask <string>("expected-book-title")); // When var books = await subjectUnderTest.Get(); // Then books.Should().HaveCount(1); books.All(b => b.Title == "expected-book-title").Should().BeTrue(); }