Swap random to use Collections.List instead of native arrays

sdk/src/main/java/com/antithesis/sdk/Random.java

@@ -2,7 +2,7 @@
 
 import com.antithesis.sdk.internal.Internal;
 
-import java.util.Optional;
+import java.util.List;
 
 /**
  * The Random class provides methods that request both structured and unstructured randomness from the Antithesis environment.
@@ -42,23 +42,20 @@ public static long getRandom() {
      * in a structured way enables it to provide more interesting
      * choices over time.
      *
-     * @param array An array of items to select from
-     * @param <T>   Type of the array member items
-     * @return Randomly selected item from the provided array.
+     * @param list An array of items to select from
+     * @param <T>  Type of the array member items
+     * @return Randomly selected item from the provided list.
      */
-    //public static <T> Optional<T> randomChoice(T[] array) {
-    public static <T> T randomChoice(T[] array) {
-        if (array.length == 0) {
-            return null; // Optional.empty();
-        } else if (array.length == 1) {
-            // return Optional.of(array[0]);
-            return array[0];
+    public static <T> T randomChoice(List<T> list) {
+        if (list.isEmpty()) {
+            return null;
+        } else if (list.size() == 1) {
+            return list.get(0);
         } else {
             // Safety: Result of modulo is always less than the divisor
             // and will always fit into an integer
-            int idx = (int) Long.remainderUnsigned(getRandom(), array.length);
-            // return Optional.of(array[idx]);
-            return array[idx];
+            int idx = (int) Long.remainderUnsigned(getRandom(), list.size());
+            return list.get(idx);
         }
     }
 }

sdk/src/test/java/com/antithesis/sdk/RandomTest.java

@@ -2,23 +2,27 @@
 
 import org.junit.jupiter.api.Test;
 
+import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.HashSet;
-import java.util.Optional;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Vector;
 
 import static org.junit.jupiter.api.Assertions.*;
 
 public class RandomTest {
     @Test
     void randomNoChoice() {
-        String[] arr = {};
-        assertEquals(Random.randomChoice(arr), null);
+        List<String> list = new ArrayList<>();
+        assertNull(Random.randomChoice(list));
     }
 
     @Test
     void randomOneChoice() {
-        String[] arr = {"ABc"};
-        assertEquals(Random.randomChoice(arr), "ABc");
+        List<String> list = new LinkedList<String>();
+        list.add("ABc");
+        assertEquals(Random.randomChoice(list), "ABc");
     }
 
     @Test
@@ -31,13 +35,12 @@ void randomFewChoices() {
         counted_items.put('c', 0);
         counted_items.put('d', 0);
 
-        Character[] all_keys = counted_items.keySet().toArray(new Character[0]);
-        assertEquals(counted_items.size(), all_keys.length);
+        List<Character> all_keys = new Vector<>(counted_items.keySet());
+        assertEquals(counted_items.size(), all_keys.size());
         for (int i = 0; i < 25; i++) {
-            Character rc = Random.randomChoice(all_keys);
-            if (rc != null) {
-                Character choice = rc;
-                counted_items.compute(choice, (key, val) -> val + 1);
+            Character choice = Random.randomChoice(all_keys);
+            if (choice != null) {
+                counted_items.computeIfPresent(choice, (key, val) -> val + 1);
             }
         }
         counted_items.forEach((key, val) -> assertNotEquals(val, 0, String.format("Did not produce the choice: %c", key)));