BAEL-9325 Code and Unit Tests for Guide to RecordBuilder (#18664)

- Add a new libraries-record-builder package with use cases for RecordBuilder.
- Provides unit tests for each of the implemented use cases.

Author: vBarbaros

libraries-7/pom.xml

@@ -42,6 +42,11 @@
             <artifactId>manifold-yaml-rt</artifactId>
             <version>${manifold.version}</version>
         </dependency>
+        <dependency>
+            <groupId>io.soabase.record-builder</groupId>
+            <artifactId>record-builder-core</artifactId>
+            <version>${record-builder.version}</version>
+        </dependency>
     </dependencies>
 
     <build>
@@ -66,6 +71,11 @@
                             <artifactId>yavi</artifactId>
                             <version>${yavi.version}</version>
                         </path>
+                        <path>
+                            <groupId>io.soabase.record-builder</groupId>
+                            <artifactId>record-builder-processor</artifactId>
+                            <version>${record-builder.version}</version>
+                        </path>
                     </annotationProcessorPaths>
                 </configuration>
             </plugin>
@@ -76,6 +86,7 @@
         <java-diff-utils.version>4.12</java-diff-utils.version>
         <yavi.version>0.14.1</yavi.version>
         <manifold.version>2024.1.20</manifold.version>
+        <record-builder.version>47</record-builder.version>
     </properties>
 
 </project>

libraries-7/src/main/java/com/baeldung/recordbuilderguide/Person.java

@@ -0,0 +1,6 @@
+package com.baeldung.recordbuilderguide;
+
+import io.soabase.recordbuilder.core.RecordBuilder;
+
+@RecordBuilder
+public record Person(String name, int age) implements PersonBuilder.With {}

libraries-7/src/main/java/com/baeldung/recordbuilderguide/RecordBuilderDemo.java

@@ -0,0 +1,49 @@
+package com.baeldung.recordbuilderguide;
+
+import java.util.function.Consumer;
+
+public class RecordBuilderDemo {
+
+    public static Person createInitialPerson() {
+        return new Person("foo", 123);
+    }
+
+    public static Person updateName(Person original) {
+        return original.withName("bar");
+    }
+
+    public static Person updateAge(Person original) {
+        return original.withAge(456);
+    }
+
+    public static Person updateBothFieldsWithBuilder(Person original) {
+        return original.with()
+          .age(101)
+          .name("baz")
+          .build();
+    }
+
+    public static Person updateWithConsumer(Person original) {
+        return original.with(p -> p.age(200).name("whatever"));
+    }
+
+    public static Person updateWithConditionalConsumer(Person original) {
+        return original.with(p -> {
+            if (p.age() > 13) {
+                p.name("Teen " + p.name());
+            } else {
+                p.name("whatever");
+            }
+        });
+    }
+
+    public static Person updateWithStaticBuilderAndConsumer(Person original) {
+        return PersonBuilder.from(original)
+          .with(p -> p.age(300).name("Manual Copy"));
+    }
+
+    public static Person updateWithStaticBuilderAndName(Person original) {
+        return PersonBuilder.from(original)
+          .withName("boop");
+    }
+}

libraries-7/src/test/java/com/baeldung/recordbuilderguide/RecordBuilderDemoUnitTest.java

@@ -0,0 +1,97 @@
+package com.baeldung.recordbuilderguide;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class RecordBuilderDemoUnitTest {
+
+    @Test
+    void givenNoInput_whenCreateInitialPerson_thenCorrectFieldsSet() {
+        Person p1 = RecordBuilderDemo.createInitialPerson();
+        assertEquals("foo", p1.name());
+        assertEquals(123, p1.age());
+    }
+
+    @Test
+    void givenPerson_whenUpdateName_thenNameChangesAndAgeUnchanged() {
+        Person p1 = RecordBuilderDemo.createInitialPerson();
+        Person p2 = RecordBuilderDemo.updateName(p1);
+
+        assertEquals("bar", p2.name());
+        assertEquals(123, p2.age());
+    }
+
+    @Test
+    void givenPerson_whenUpdateAge_thenAgeChangesAndNameUnchanged() {
+        Person p2 = RecordBuilderDemo.updateName(RecordBuilderDemo.createInitialPerson());
+        Person p3 = RecordBuilderDemo.updateAge(p2);
+
+        assertEquals("bar", p3.name());
+        assertEquals(456, p3.age());
+    }
+
+    @Test
+    void givenPerson_whenUpdateBothFieldsWithBuilder_thenBothFieldsChange() {
+        Person p3 = RecordBuilderDemo.updateAge(
+                        RecordBuilderDemo.updateName(
+                            RecordBuilderDemo.createInitialPerson()));
+        Person p4 = RecordBuilderDemo.updateBothFieldsWithBuilder(p3);
+
+        assertEquals("baz", p4.name());
+        assertEquals(101, p4.age());
+    }
+
+    @Test
+    void givenPerson_whenUpdateWithConsumer_thenFieldsChangeCorrectly() {
+        Person p4 = RecordBuilderDemo.updateBothFieldsWithBuilder(
+                        RecordBuilderDemo.updateAge(
+                            RecordBuilderDemo.updateName(
+                                RecordBuilderDemo.createInitialPerson())));
+        Person p5 = RecordBuilderDemo.updateWithConsumer(p4);
+
+        assertEquals("whatever", p5.name());
+        assertEquals(200, p5.age());
+    }
+
+    @Test
+    void givenPerson_whenUpdateWithConditionalConsumer_thenNameIsConditionallySet() {
+        Person p5 = RecordBuilderDemo.updateWithConsumer(
+                        RecordBuilderDemo.updateBothFieldsWithBuilder(
+                            RecordBuilderDemo.updateAge(
+                                RecordBuilderDemo.updateName(
+                                    RecordBuilderDemo.createInitialPerson()))));
+        Person p6 = RecordBuilderDemo.updateWithConditionalConsumer(p5);
+
+        assertEquals("Teen whatever", p6.name());
+        assertEquals(200, p6.age());
+    }
+
+    @Test
+    void givenPerson_whenUpdateWithStaticBuilderAndConsumer_thenFieldsAreUpdated() {
+        Person p6 = RecordBuilderDemo.updateWithConditionalConsumer(
+                        RecordBuilderDemo.updateWithConsumer(
+                            RecordBuilderDemo.updateBothFieldsWithBuilder(
+                                RecordBuilderDemo.updateAge(
+                                    RecordBuilderDemo.updateName(
+                                        RecordBuilderDemo.createInitialPerson())))));
+        Person p7 = RecordBuilderDemo.updateWithStaticBuilderAndConsumer(p6);
+
+        assertEquals("Manual Copy", p7.name());
+        assertEquals(300, p7.age());
+    }
+
+    @Test
+    void givenPerson_whenUpdateWithStaticBuilderAndName_thenOnlyNameChanges() {
+        Person p6 = RecordBuilderDemo.updateWithConditionalConsumer(
+                        RecordBuilderDemo.updateWithConsumer(
+                            RecordBuilderDemo.updateBothFieldsWithBuilder(
+                                RecordBuilderDemo.updateAge(
+                                    RecordBuilderDemo.updateName(
+                                        RecordBuilderDemo.createInitialPerson())))));
+        Person p8 = RecordBuilderDemo.updateWithStaticBuilderAndName(p6);
+
+        assertEquals("boop", p8.name());
+        assertEquals(200, p8.age());
+    }
+}