From 9a84075dbd9be34ec90bb03465fe05b1c4ff7f60 Mon Sep 17 00:00:00 2001
From: Christian Jaimes <christian.jaimes@oracle>
Date: Thu, 21 Apr 2022 09:29:37 -0400
Subject: [PATCH] added randomDirection method to Enum. Created
 RandomEnumGenerator. Added corresponding Unit Tests

---
 .../java/com/baeldung/enums/Direction.java    | 14 ++++++++++
 .../baeldung/enums/RandomEnumGenerator.java   | 17 ++++++++++++
 .../baeldung/enums/RandomEnumUnitTest.java    | 27 +++++++++++++++++++
 3 files changed, 58 insertions(+)
 create mode 100644 core-java-modules/core-java-lang-oop-types-2/src/main/java/com/baeldung/enums/RandomEnumGenerator.java
 create mode 100644 core-java-modules/core-java-lang-oop-types-2/src/test/java/com/baeldung/enums/RandomEnumUnitTest.java

diff --git a/core-java-modules/core-java-lang-oop-types-2/src/main/java/com/baeldung/enums/Direction.java b/core-java-modules/core-java-lang-oop-types-2/src/main/java/com/baeldung/enums/Direction.java
index 935aca4d65..76b63bdf50 100644
--- a/core-java-modules/core-java-lang-oop-types-2/src/main/java/com/baeldung/enums/Direction.java
+++ b/core-java-modules/core-java-lang-oop-types-2/src/main/java/com/baeldung/enums/Direction.java
@@ -1,11 +1,25 @@
 package com.baeldung.enums;
 
+import java.util.Random;
+
 /**
  * Represents directions.
  */
 public enum Direction {
     EAST, WEST, SOUTH, NORTH;
 
+    private static final Random PRNG = new Random();
+
+    /**
+     * Generate a random direction.
+     *
+     * @return a random direction
+     */
+    public static Direction randomDirection() {
+        Direction[] directions = values();
+        return directions[PRNG.nextInt(directions.length)];
+    }
+
     /**
      * Finds direction by name.
      *
diff --git a/core-java-modules/core-java-lang-oop-types-2/src/main/java/com/baeldung/enums/RandomEnumGenerator.java b/core-java-modules/core-java-lang-oop-types-2/src/main/java/com/baeldung/enums/RandomEnumGenerator.java
new file mode 100644
index 0000000000..ea27286044
--- /dev/null
+++ b/core-java-modules/core-java-lang-oop-types-2/src/main/java/com/baeldung/enums/RandomEnumGenerator.java
@@ -0,0 +1,17 @@
+package com.baeldung.enums;
+
+import java.util.Random;
+
+public class RandomEnumGenerator<T extends Enum<T>> {
+
+    private static final Random PRNG = new Random();
+    private final T[] values;
+
+    public RandomEnumGenerator(Class<T> e) {
+        values = e.getEnumConstants();
+    }
+
+    public T randomEnum() {
+        return values[PRNG.nextInt(values.length)];
+    }
+}
\ No newline at end of file
diff --git a/core-java-modules/core-java-lang-oop-types-2/src/test/java/com/baeldung/enums/RandomEnumUnitTest.java b/core-java-modules/core-java-lang-oop-types-2/src/test/java/com/baeldung/enums/RandomEnumUnitTest.java
new file mode 100644
index 0000000000..937b376c29
--- /dev/null
+++ b/core-java-modules/core-java-lang-oop-types-2/src/test/java/com/baeldung/enums/RandomEnumUnitTest.java
@@ -0,0 +1,27 @@
+package com.baeldung.enums;
+
+import org.assertj.core.api.Assertions;
+import org.junit.Test;
+
+import java.util.Optional;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatIllegalArgumentException;
+
+public class RandomEnumUnitTest {
+
+    @Test
+    public void givenEnumType_whenUsingStaticMethod_valueIsRandomlyGenerated() {
+        Direction direction = Direction.randomDirection();
+        assertThat(direction).isNotNull();
+        assertThat(direction instanceof Direction);
+    }
+
+    @Test
+    public void givenEnumType_whenGeneratingRandomValue_valueIsOfClassAndNotNull() {
+        RandomEnumGenerator reg = new RandomEnumGenerator(Direction.class);
+        Object direction = reg.randomEnum();
+        assertThat(direction).isNotNull();
+        assertThat(direction instanceof Direction);
+    }
+}