Add prototype design pattern with test case (#50)

Author: mperor

DesignPatterns/README.md

@@ -15,6 +15,7 @@ This project explores various design patterns and their implementations in moder
 
 - [Factory](src/main/java/pl/mperor/lab/java/design/pattern/creational/factory) 🏭
 - [Builder](src/main/java/pl/mperor/lab/java/design/pattern/creational/builder) 🏗️
+- [Prototype](src/main/java/pl/mperor/lab/java/design/pattern/creational/prototype) 🧬
 - [Singleton](src/main/java/pl/mperor/lab/java/design/pattern/creational/singleton) 1️⃣
 
 ### Structural Design Patterns 🎁

DesignPatterns/src/main/java/pl/mperor/lab/java/design/pattern/creational/prototype/DNA.java

@@ -0,0 +1,4 @@
+package pl.mperor.lab.java.design.pattern.creational.prototype;
+
+public record DNA(String sequence) {
+}

DesignPatterns/src/main/java/pl/mperor/lab/java/design/pattern/creational/prototype/Sheep.java

@@ -0,0 +1,74 @@
+package pl.mperor.lab.java.design.pattern.creational.prototype;
+
+import java.time.Year;
+import java.util.function.Function;
+
+public class Sheep {
+
+    private String name;
+    private DNA dna;
+    private Year yearOfBirth;
+    private Breed breed;
+
+    private Sheep(Sheep sheep) {
+        this.name = sheep.name;
+        this.dna = sheep.dna;
+        this.yearOfBirth = Year.now();
+        this.breed = sheep.breed;
+    }
+
+    public Sheep(String name, DNA dna, Year yearOfBirth, Breed breed) {
+        this.name = name;
+        this.dna = dna;
+        this.yearOfBirth = yearOfBirth;
+        this.breed = breed;
+    }
+
+    String getName() {
+        return name;
+    }
+
+    void setName(String name) {
+        this.name = name;
+    }
+
+    DNA getDna() {
+        return dna;
+    }
+
+    Year getYearOfBirth() {
+        return yearOfBirth;
+    }
+
+    Breed getBreed() {
+        return breed;
+    }
+
+    public Sheep clone(Function<CloneBuilder, Sheep> cloning) {
+        return cloning.apply(new CloneBuilder(new Sheep(this)));
+    }
+
+    public class CloneBuilder {
+        private Sheep clone;
+
+        public CloneBuilder(Sheep clone) {
+            this.clone = clone;
+        }
+
+        public CloneBuilder name(String name) {
+            clone.name = name;
+            return this;
+        }
+
+        public Sheep build() {
+            return clone;
+        }
+    }
+
+    enum Breed {
+        MERINO,
+        SUFFOLK,
+        DORSET,
+        HAMPSHIRE
+    }
+}

DesignPatterns/src/test/java/pl/mperor/lab/java/design/pattern/creational/prototype/SheepPrototypeTest.java

@@ -0,0 +1,22 @@
+package pl.mperor.lab.java.design.pattern.creational.prototype;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+import java.time.Year;
+
+public class SheepPrototypeTest {
+
+    @Test
+    public void testSheepCloning() {
+        Sheep originalSheep = new Sheep("Dolly", new DNA("AGCT"), Year.of(2010), Sheep.Breed.MERINO);
+        Sheep clonedSheep = originalSheep.clone(builder -> builder
+                .name("Molly")
+                .build()
+        );
+        Assertions.assertNotSame(originalSheep, clonedSheep);
+        Assertions.assertSame(originalSheep.getDna(), clonedSheep.getDna());
+        Assertions.assertSame(originalSheep.getBreed(), clonedSheep.getBreed());
+        Assertions.assertNotEquals(originalSheep.getYearOfBirth(), clonedSheep.getYearOfBirth());
+    }
+}