From b9484b244b683f54882bba6d59f82ed75867f801 Mon Sep 17 00:00:00 2001
From: Tomasz Lelek <tomekl007@gmail.com>
Date: Sun, 30 Apr 2017 08:21:11 +0200
Subject: [PATCH] BAEL-881 copyOnWriteArrayList tests (#1750)

---
 .../copyonwrite/CopyOnWriteArrayListTest.java | 53 +++++++++++++++++++
 1 file changed, 53 insertions(+)
 create mode 100644 core-java/src/test/java/com/baeldung/concurrent/copyonwrite/CopyOnWriteArrayListTest.java

diff --git a/core-java/src/test/java/com/baeldung/concurrent/copyonwrite/CopyOnWriteArrayListTest.java b/core-java/src/test/java/com/baeldung/concurrent/copyonwrite/CopyOnWriteArrayListTest.java
new file mode 100644
index 0000000000..c71c193372
--- /dev/null
+++ b/core-java/src/test/java/com/baeldung/concurrent/copyonwrite/CopyOnWriteArrayListTest.java
@@ -0,0 +1,53 @@
+package com.baeldung.concurrent.copyonwrite;
+
+
+import org.junit.Test;
+
+import java.util.Iterator;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.concurrent.CopyOnWriteArrayList;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+
+public class CopyOnWriteArrayListTest {
+
+    @Test
+    public void givenCopyOnWriteList_whenIterateAndAddElementToUnderneathList_thenShouldNotChangeIterator() {
+        //given
+        final CopyOnWriteArrayList<Integer> numbers =
+                new CopyOnWriteArrayList<>(new Integer[]{1, 3, 5, 8});
+
+        //when
+        Iterator<Integer> iterator = numbers.iterator();
+        numbers.add(10);
+
+        //then
+        List<Integer> result = new LinkedList<>();
+        iterator.forEachRemaining(result::add);
+        assertThat(result).containsOnly(1, 3, 5, 8);
+
+        //and
+        Iterator<Integer> iterator2 = numbers.iterator();
+        List<Integer> result2 = new LinkedList<>();
+        iterator2.forEachRemaining(result2::add);
+
+        //then
+        assertThat(result2).containsOnly(1, 3, 5, 8, 10);
+
+    }
+
+    @Test(expected = UnsupportedOperationException.class)
+    public void givenCopyOnWriteList_whenIterateOverItAndTryToRemoveElement_thenShouldThrowException() {
+        //given
+        final CopyOnWriteArrayList<Integer> numbers =
+                new CopyOnWriteArrayList<>(new Integer[]{1, 3, 5, 8});
+
+        //when
+        Iterator<Integer> iterator = numbers.iterator();
+        while (iterator.hasNext()) {
+            iterator.remove();
+        }
+    }
+}