BAEL-7735: Add test case demonstrating TestNG SoftAssert (#16443)

* BAEL-7735: Add test case demonstrating TestNG SoftAssert

* Update package

* Move Book and BookService to separate classes

testing-modules/testng/src/test/java/com/baeldung/testng/softassert/Book.java

@@ -0,0 +1,34 @@
+package com.baeldung.testng.softassert;
+
+public class Book {
+    private String isbn;
+    private String title;
+    private String author;
+
+    public Book() {
+    }
+
+    public String getIsbn() {
+        return isbn;
+    }
+
+    public void setIsbn(String isbn) {
+        this.isbn = isbn;
+    }
+
+    public String getTitle() {
+        return title;
+    }
+
+    public void setTitle(String title) {
+        this.title = title;
+    }
+
+    public String getAuthor() {
+        return author;
+    }
+
+    public void setAuthor(String author) {
+        this.author = author;
+    }
+}

testing-modules/testng/src/test/java/com/baeldung/testng/softassert/BookService.java

@@ -0,0 +1,5 @@
+package com.baeldung.testng.softassert;
+
+public interface BookService {
+    Book getBook(String isbn);
+}

testing-modules/testng/src/test/java/com/baeldung/testng/softassert/SoftAssertionUnitTest.java

@@ -0,0 +1,43 @@
+package com.baeldung.testng.softassert;
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+import static org.testng.Assert.assertNotNull;
+import static org.testng.Assert.assertTrue;
+
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+import org.testng.annotations.BeforeMethod;
+import org.testng.annotations.Test;
+import org.testng.asserts.SoftAssert;
+
+public class SoftAssertionUnitTest {
+
+    private BookService bookService;
+
+    @BeforeMethod
+    void setup() {
+        bookService = mock(BookService.class);
+        Book book = new Book();
+        when(bookService.getBook(any()))
+            .thenReturn(book);
+    }
+
+    @Test
+    void givenBookWithNullFields_whenUsingMultipleAssertions_thenUseSoftAssert() {
+        Book gatsby = bookService.getBook("9780743273565");
+
+        // Traditional assertions - uncomment to see the test fail, only running the first assertion
+        // assertNotNull(gatsby.isbn, "ISBN");
+        // assertNotNull(gatsby.title, "title");
+        // assertNotNull(gatsby.author, "author");
+
+        // SoftAssert - uncomment to see the test fail, but with all assertions run
+        // SoftAssert softAssert = new SoftAssert();
+        // softAssert.assertNotNull(gatsby.isbn, "ISBN");
+        // softAssert.assertNotNull(gatsby.title, "title");
+        // softAssert.assertNotNull(gatsby.author, "author");
+        // softAssert.assertAll();
+    }
+}