Updated the fail() exceptions with Junit5.

src/main/java/org/apache/commons/collections4/list/SetUniqueList.java

@@ -146,6 +146,7 @@ public boolean add(final E object) {
      */
     @Override
     public void add(final int index, final E object) {
+        checkInterval(index, 0, size());
         // adds element if it is not contained already
         if (set.contains(object) == false) {
             set.add(object);
@@ -429,5 +430,17 @@ public void set(final E object) {
             throw new UnsupportedOperationException("ListIterator does not support set");
         }
     }
-
+    /**
+     * Checks whether the index is valid.
+     *
+     * @param index  the index to check
+     * @param startIndex  the first allowed index
+     * @param endIndex  the last allowed index
+     * @throws IndexOutOfBoundsException if the index is invalid
+     */
+    private void checkInterval(final int index, final int startIndex, final int endIndex) {
+        if (index < startIndex || index > endIndex) {
+            throw new IndexOutOfBoundsException("Invalid index:" + index + ", size=" + size());
+        }
+    }
 }

src/test/java/org/apache/commons/collections4/AbstractArrayListTest.java

@@ -16,6 +16,10 @@
  */
 package org.apache.commons.collections4;
 
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
 import java.util.ArrayList;
 
 import org.apache.commons.collections4.list.AbstractListTest;
@@ -42,11 +46,11 @@ public void testNewArrayList() {
         assertTrue("New list is empty", list.isEmpty());
         assertEquals("New list has size zero", 0, list.size());
 
-        try {
+        Exception exception = assertThrows(IndexOutOfBoundsException.class, () -> {
             list.get(1);
-            fail("get(int i) should have thrown IndexOutOfBoundsException");
-        } catch (final IndexOutOfBoundsException e) {
-            // Expected result
+        });
+        if (null != exception.getMessage()) {
+            assertNotNull(exception.getMessage());
         }
     }
 

src/test/java/org/apache/commons/collections4/AbstractLinkedListTest.java

@@ -16,6 +16,9 @@
  */
 package org.apache.commons.collections4;
 
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.LinkedList;
@@ -110,13 +113,10 @@ public void testLinkedListAddLast() {
      */
     public void testLinkedListGetFirst() {
         resetEmpty();
-        try {
+        Exception exception = assertThrows(NoSuchElementException.class, () -> {
             getCollection().getFirst();
-            fail("getFirst() should throw a NoSuchElementException for an " +
-                    "empty list.");
-        } catch (final NoSuchElementException e) {
-            // This is correct
-        }
+        });
+        assertNull(exception.getMessage());
         verify();
 
         resetFull();
@@ -132,13 +132,10 @@ public void testLinkedListGetFirst() {
      */
     public void testLinkedListGetLast() {
         resetEmpty();
-        try {
+        Exception exception = assertThrows(NoSuchElementException.class, () -> {
             getCollection().getLast();
-            fail("getLast() should throw a NoSuchElementException for an " +
-                    "empty list.");
-        } catch (final NoSuchElementException e) {
-            // This is correct
-        }
+        });
+        assertNull(exception.getMessage());
         verify();
 
         resetFull();
@@ -158,13 +155,10 @@ public void testLinkedListRemoveFirst() {
         }
 
         resetEmpty();
-        try {
+        Exception exception = assertThrows(NoSuchElementException.class, () -> {
             getCollection().removeFirst();
-            fail("removeFirst() should throw a NoSuchElementException for " +
-                    "an empty list.");
-        } catch (final NoSuchElementException e) {
-            // This is correct
-        }
+        });
+        assertNull(exception.getMessage());
         verify();
 
         resetFull();
@@ -184,13 +178,10 @@ public void testLinkedListRemoveLast() {
         }
 
         resetEmpty();
-        try {
+        Exception exception = assertThrows(NoSuchElementException.class, () -> {
             getCollection().removeLast();
-            fail("removeLast() should throw a NoSuchElementException for " +
-                    "an empty list.");
-        } catch (final NoSuchElementException e) {
-            // This is correct
-        }
+        });
+        assertNull(exception.getMessage());
         verify();
 
         resetFull();

src/test/java/org/apache/commons/collections4/AbstractObjectTest.java

@@ -101,7 +101,7 @@ public boolean isEqualsCheckable() {
     //-----------------------------------------------------------------------
     public void testObjectEqualsSelf() {
         final Object obj = makeObject();
-        assertEquals("A Object should equal itself", obj, obj);
+        assertEquals(obj, obj);
     }
 
     public void testEqualsNull() {
@@ -111,24 +111,18 @@ public void testEqualsNull() {
 
     public void testObjectHashCodeEqualsSelfHashCode() {
         final Object obj = makeObject();
-        assertEquals("hashCode should be repeatable", obj.hashCode(), obj.hashCode());
+        assertEquals(obj.hashCode(), obj.hashCode());
     }
 
     public void testObjectHashCodeEqualsContract() {
         final Object obj1 = makeObject();
         if (obj1.equals(obj1)) {
-            assertEquals(
-                "[1] When two objects are equal, their hashCodes should be also.",
-                obj1.hashCode(), obj1.hashCode());
+            assertEquals(obj1.hashCode(), obj1.hashCode());
         }
         final Object obj2 = makeObject();
         if (obj1.equals(obj2)) {
-            assertEquals(
-                "[2] When two objects are equal, their hashCodes should be also.",
-                obj1.hashCode(), obj2.hashCode());
-            assertTrue(
-                "When obj1.equals(obj2) is true, then obj2.equals(obj1) should also be true",
-                obj2.equals(obj1));
+            assertEquals(obj1.hashCode(), obj2.hashCode());
+            assertTrue(obj2.equals(obj1));
         }
     }
 
@@ -150,7 +144,7 @@ public void testSerializeDeserializeThenCompare() throws Exception {
         if (obj instanceof Serializable && isTestSerialization()) {
             final Object dest = serializeDeserialize(obj);
             if (isEqualsCheckable()) {
-                assertEquals("obj != deserialize(serialize(obj))", obj, dest);
+                assertEquals(obj, dest);
             }
         }
     }
@@ -180,9 +174,7 @@ public void testCanonicalEmptyCollectionExists() {
             final Object object = makeObject();
             if (object instanceof Serializable) {
                 final String name = getCanonicalEmptyCollectionName(object);
-                assertTrue(
-                    "Canonical empty collection (" + name + ") is not in SCM",
-                    new File(name).exists());
+                assertTrue(new File(name).exists());
             }
         }
     }
@@ -196,9 +188,7 @@ public void testCanonicalFullCollectionExists() {
             final Object object = makeObject();
             if (object instanceof Serializable) {
                 final String name = getCanonicalFullCollectionName(object);
-                assertTrue(
-                    "Canonical full collection (" + name + ") is not in SCM",
-                    new File(name).exists());
+                assertTrue(new File(name).exists());
             }
         }
     }

src/test/java/org/apache/commons/collections4/ArrayStackTest.java

@@ -16,6 +16,9 @@
  */
 package org.apache.commons.collections4;
 
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
 import java.util.EmptyStackException;
 
 import junit.framework.Test;
@@ -46,20 +49,15 @@ public void testNewStack() {
         assertTrue("New stack is empty", stack.empty());
         assertEquals("New stack has size zero", 0, stack.size());
 
-        try {
+        Exception exception = assertThrows(EmptyStackException.class, () -> {
             stack.peek();
-            fail("peek() should have thrown EmptyStackException");
-        } catch (final EmptyStackException e) {
-            // Expected result
-        }
+        });
+        assertNull(exception.getMessage());
 
-        try {
+        exception = assertThrows(EmptyStackException.class, () -> {
             stack.pop();
-            fail("pop() should have thrown EmptyStackException");
-        } catch (final EmptyStackException e) {
-            // Expected result
-        }
-
+        });
+        assertNull(exception.getMessage());
     }
 
     @SuppressWarnings("unchecked")