Simple stack from list

Author: deepak-malik

src/com/deepak/data/structures/Stack/SimpleStackFromList.java

@@ -1,5 +1,5 @@
 /**
- * Data-Structures-And-Algorithms-in-Java
+ * Data-Structures-In-Java
  * SimpleStackFromList.java
  */
 package com.deepak.data.structures.Stack;
@@ -8,37 +8,19 @@
 
 /**
  * Class implementing simple stack based on the list
+ * 
  * @author Deepak
  */
 public class SimpleStackFromList {
 
-	/**
-	 * Sample implementation of stack
-	 * @param args
-	 */
-	public static void main(String[] args) {
-		SimpleStackFromList stack = new SimpleStackFromList();
-		System.out.println("Creating a fresh Stack");
-		System.out.println("Size of Stack => " + stack.size());
-		System.out.println("Is Stack Empty => " + stack.isEmpty());
-		System.out.println("Inserting two items in Stack.");
-		stack.push(10);
-		stack.push(20);
-		System.out.println("After Insertion, Size of Stack => " + stack.size());
-		System.out.println("After Insertion, Is Stack Empty => " + stack.isEmpty());
-		System.out.println("Removing an item from Stack.");
-		stack.pop();
-		System.out.println("After Removal, Size of Stack => " + stack.size());
-		System.out.println("Top element on Stack => " + stack.peek());
-	}
-
 	/**
 	 * Linked list to hold items
 	 */
 	private LinkedList<Object> list = new LinkedList<>();
 
 	/**
 	 * Method to push a item on top of stack
+	 * 
 	 * @param item
 	 */
 	public void push(Object item) {
@@ -47,6 +29,7 @@ public void push(Object item) {
 
 	/**
 	 * Method to remove a item from top of stack
+	 * 
 	 * @return {@link Object}
 	 */
 	public Object pop() {
@@ -55,6 +38,7 @@ public Object pop() {
 
 	/**
 	 * Method to look up top item in stack
+	 * 
 	 * @return {@link Object}
 	 */
 	public Object peek() {
@@ -63,6 +47,7 @@ public Object peek() {
 
 	/**
 	 * Method to check size of the stack
+	 * 
 	 * @return {@link int}
 	 */
 	public int size() {
@@ -71,6 +56,7 @@ public int size() {
 
 	/**
 	 * Method to check if stack is empty
+	 * 
 	 * @return {@link boolean}
 	 */
 	public boolean isEmpty() {

test/com/deepak/data/structures/Stack/SimpleStackTest.java

@@ -0,0 +1,67 @@
+/**
+ * Data-Structures-in-Java
+ * SimpleStackTest.java
+ */
+package com.deepak.data.structures.Stack;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+public class SimpleStackTest {
+
+	/**
+	 * Test case for push feature
+	 */
+	@Test
+	public void testPush() {
+		SimpleStackFromList stack = new SimpleStackFromList();
+		Assert.assertTrue(stack.isEmpty());
+		Assert.assertTrue(stack.size() == 0);
+		stack.push(3);
+		Assert.assertFalse(stack.isEmpty());
+		Assert.assertTrue(stack.size() == 1);
+		stack.push(7);
+		stack.push(31);
+		Assert.assertTrue(stack.size() == 3);
+	}
+
+	/**
+	 * Test case for pop feature
+	 */
+	@Test
+	public void testPop() {
+		SimpleStackFromList stack = new SimpleStackFromList();
+		Assert.assertTrue(stack.isEmpty());
+		Assert.assertTrue(stack.size() == 0);
+		stack.push(3);
+		stack.push(17);
+		stack.push(35);
+		stack.push(13);
+		Assert.assertTrue(stack.size() == 4);
+		Assert.assertEquals(stack.pop(), 13);
+		Assert.assertEquals(stack.pop(), 35);
+		Assert.assertEquals(stack.pop(), 17);
+		Assert.assertTrue(stack.size() == 1);
+	}
+
+	/**
+	 * Test case for peek feature
+	 */
+	@Test
+	public void testPeek() {
+		SimpleStackFromList stack = new SimpleStackFromList();
+		Assert.assertTrue(stack.isEmpty());
+		Assert.assertTrue(stack.size() == 0);
+		stack.push(3);
+		stack.push(17);
+		stack.push(35);
+		stack.push(13);
+		Assert.assertTrue(stack.size() == 4);
+		Assert.assertEquals(stack.peek(), 13);
+		Assert.assertTrue(stack.size() == 4);
+		stack.pop();
+		Assert.assertTrue(stack.size() == 3);
+		Assert.assertEquals(stack.peek(), 35);
+	}
+
+}