BAEL-7615 - Implement the Builder Pattern in Java 8 (#16399)

* BAEL-7255 - Implementing GraphQL Mutation without Returning Data

* BAEL-7615 - Implement the Builder Pattern in Java 8

* BAEL-7615 - Implement the Builder Pattern in Java 8

patterns-modules/design-patterns-creational-2/src/test/java/com/baeldung/builder/implementation/BuilderImplementationUnitTest.java

@@ -0,0 +1,50 @@
+package com.baeldung.builder.implementation;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.api.Test;
+
+public class BuilderImplementationUnitTest {
+
+    @Test
+    void givenClassicBuilder_whenBuild_thenReturnObject() {
+
+        Post post = new Post.Builder()
+          .title("Java Builder Pattern")
+          .text("Explaining how to implement the Builder Pattern in Java")
+          .category("Programming")
+          .build();
+
+        assertEquals("Java Builder Pattern", post.getTitle());
+        assertEquals("Explaining how to implement the Builder Pattern in Java", post.getText());
+        assertEquals("Programming", post.getCategory());
+    }
+
+    @Test
+    void givenGenericBuilder_whenBuild_thenReturnObject() {
+
+        Post post = GenericBuilder.of(Post::new)
+          .with(Post::setTitle, "Java Builder Pattern")
+          .with(Post::setText, "Explaining how to implement the Builder Pattern in Java")
+          .with(Post::setCategory, "Programming")
+          .build();
+
+        assertEquals("Java Builder Pattern", post.getTitle());
+        assertEquals("Explaining how to implement the Builder Pattern in Java", post.getText());
+        assertEquals("Programming", post.getCategory());
+    }
+
+    @Test
+    void givenLombokBuilder_whenBuild_thenReturnObject() {
+
+        LombokPost post = LombokPost.builder()
+          .title("Java Builder Pattern")
+          .text("Explaining how to implement the Builder Pattern in Java")
+          .category("Programming")
+          .build();
+
+        assertEquals("Java Builder Pattern", post.getTitle());
+        assertEquals("Explaining how to implement the Builder Pattern in Java", post.getText());
+        assertEquals("Programming", post.getCategory());
+    }
+}