From 275011f836c9394f402b8872a32d917809a50fcd Mon Sep 17 00:00:00 2001
From: Christopher Ng <babedroid@gmail.com>
Date: Wed, 16 Oct 2019 21:47:10 +0700
Subject: [PATCH] :sparkles: Introduce Prototype pattern

---
 README.md                             | 47 +++++++++++++++++++++++++++
 patterns/src/test/kotlin/Prototype.kt | 36 ++++++++++++++++++++
 2 files changed, 83 insertions(+)
 create mode 100644 patterns/src/test/kotlin/Prototype.kt

diff --git a/README.md b/README.md
index 726d78e..0ffdf0a 100644
--- a/README.md
+++ b/README.md
@@ -20,6 +20,7 @@ Inspired by [Design-Patterns-In-Swift](https://github.com/ochococo/Design-Patter
 * [Creational Patterns](#creational)
 	* [Builder / Assembler](#builder--assembler)
 	* [Factory Method](#factory-method)
+	* [Prototype](#prototype)
 	* [Singleton](#singleton)
 	* [Abstract Factory](#abstract-factory)
 * [Structural Patterns](#structural)
@@ -714,6 +715,52 @@ US currency: USD
 UK currency: No Currency Code Available
 ```
 
+[Prototype](/patterns/src/test/kotlin/Prototype.kt)
+------------
+
+The prototype pattern is used to instantiate a new object by copying all of the properties of an existing object, 
+creating an independent clone. This practise is particularly useful when the construction of a new object is inefficient.
+
+#### Example:
+
+```kotlin
+open class Cat : Cloneable {
+    private var sound = ""
+    private var species = ""
+
+    init {
+        sound = "Meow"
+        species = "Ordinary"
+    }
+
+    public override fun clone(): Cat = Cat()
+
+    fun powerUp() {
+        sound = "MEOW!!!"
+        species = "Super cat"
+    }
+}
+
+fun makeSuperCat(cat: Cat): Cat = cat.apply { powerUp() }
+```
+
+#### Usage
+
+```kotlin
+val ordinaryCat = Cat()
+val copiedCat = ordinaryCat.clone()
+val superCat = makeSuperCat(copiedCat)
+println("Copied cat: $copiedCat")
+println("Super cat: $superCat")
+```
+
+#### Output
+
+```
+Copied cat: Cat@6e1567f1
+Super cat: Cat@6e1567f1
+```
+
 [Singleton](/patterns/src/test/kotlin/Singleton.kt)
 ------------
 
diff --git a/patterns/src/test/kotlin/Prototype.kt b/patterns/src/test/kotlin/Prototype.kt
new file mode 100644
index 0000000..f7d96bc
--- /dev/null
+++ b/patterns/src/test/kotlin/Prototype.kt
@@ -0,0 +1,36 @@
+import org.junit.jupiter.api.Assertions.assertEquals
+import org.junit.jupiter.api.Test
+
+open class Cat : Cloneable {
+    var sound = ""
+    var species = ""
+
+    init {
+        sound = "Meow"
+        species = "Ordinary"
+    }
+
+    public override fun clone(): Cat = Cat()
+
+    fun powerUp() {
+        sound = "MEOW!!!"
+        species = "Super cat"
+    }
+}
+
+fun makeSuperCat(cat: Cat): Cat = cat.apply { powerUp() }
+
+class PrototypeTest {
+
+    @Test
+    fun Prototype() {
+        val ordinaryCat = Cat()
+        val copiedCat = ordinaryCat.clone()
+
+        assertEquals(ordinaryCat.sound, copiedCat.sound)
+
+        val superCat = makeSuperCat(copiedCat)
+
+        assertEquals(copiedCat.sound, superCat.sound)
+    }
+}