BAEL-1310: Code for Quick Guide to Stack. (#2993)

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Wosin 2017-11-09 20:52:58 +01:00 committed by Grzegorz Piwowarek
parent 182a7525f2
commit 6a8ecab163
1 changed files with 137 additions and 0 deletions

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package com.baeldung.stack;
import static org.hamcrest.CoreMatchers.equalTo;
import static org.junit.Assert.*;
import java.util.Arrays;
import java.util.List;
import java.util.ListIterator;
import java.util.Stack;
import org.junit.Test;
public class StackUnitTest {
@Test
public void whenStackIsCreated_thenItHasSize0() {
Stack intStack = new Stack();
assertEquals(0, intStack.size());
}
@Test
public void givenEmptyStack_whenElementIsPushed_thenStackSizeisIncreased() {
Stack intStack = new Stack();
intStack.push(1);
assertEquals(1, intStack.size());
}
@Test
public void givenEmptyStack_whenMultipleElementsArePushed_thenStackSizeisIncreased() {
Stack intStack = new Stack();
List<Integer> intList = Arrays.asList(1, 2, 3, 4, 5, 6, 7);
boolean result = intStack.addAll(intList);
assertTrue(result);
assertEquals(7, intList.size());
}
@Test
public void whenElementIsPoppedFromStack_thenElementIsRemovedAndSizeChanges() {
Stack<Integer> intStack = new Stack();
intStack.push(5);
intStack.pop();
assertTrue(intStack.isEmpty());
}
@Test
public void whenElementIsPeeked_thenElementIsNotRemovedAndSizeDoesNotChange() {
Stack<Integer> intStack = new Stack();
intStack.push(5);
intStack.peek();
assertEquals(1, intStack.search(5));
assertEquals(1, intStack.size());
}
@Test
public void whenElementIsOnStack_thenSearchReturnsItsDistanceFromTheTop() {
Stack<Integer> intStack = new Stack();
intStack.push(5);
assertEquals(1, intStack.search(5));
}
@Test
public void whenElementIsOnStack_thenIndexOfReturnsItsIndex() {
Stack<Integer> intStack = new Stack();
intStack.push(5);
int indexOf = intStack.indexOf(5);
assertEquals(0, indexOf);
}
@Test
public void whenMultipleElementsAreOnStack_thenIndexOfReturnsLastElementIndex() {
Stack<Integer> intStack = new Stack();
intStack.push(5);
intStack.push(5);
intStack.push(5);
int lastIndexOf = intStack.lastIndexOf(5);
assertEquals(2, lastIndexOf);
}
@Test
public void givenElementOnStack_whenRemoveElementIsInvoked_thenElementIsRemoved() {
Stack<Integer> intStack = new Stack();
intStack.push(5);
intStack.push(5);
intStack.removeElement(5);
assertEquals(1, intStack.size());
}
@Test
public void givenElementOnStack_whenRemoveElementAtIsInvoked_thenElementIsRemoved() {
Stack<Integer> intStack = new Stack();
intStack.push(5);
intStack.push(7);
intStack.removeElementAt(1);
assertEquals(-1, intStack.search(7));
}
@Test
public void givenElementsOnStack_whenRemoveAllElementsIsInvoked_thenAllElementsAreRemoved() {
Stack<Integer> intStack = new Stack();
intStack.push(5);
intStack.push(7);
intStack.removeAllElements();
assertTrue(intStack.isEmpty());
}
@Test
public void givenElementsOnStack_whenRemoveAllIsInvoked_thenAllElementsFromCollectionAreRemoved() {
Stack<Integer> intStack = new Stack();
List<Integer> intList = Arrays.asList(1, 2, 3, 4, 5, 6, 7);
intStack.addAll(intList);
intStack.add(500);
intStack.removeAll(intList);
assertEquals(1, intStack.size());
}
@Test
public void givenElementsOnStack_whenRemoveIfIsInvoked_thenAllElementsSatysfyingConditionAreRemoved() {
Stack<Integer> intStack = new Stack();
List<Integer> intList = Arrays.asList(1, 2, 3, 4, 5, 6, 7);
intStack.addAll(intList);
intStack.removeIf(element -> element < 6);
assertEquals(2, intStack.size());
}
@Test
public void whenAnotherStackCreatedWhileTraversingStack_thenStacksAreEqual() {
Stack<Integer> intStack = new Stack<>();
List<Integer> intList = Arrays.asList(1, 2, 3, 4, 5, 6, 7);
intStack.addAll(intList);
ListIterator<Integer> it = intStack.listIterator();
Stack<Integer> result = new Stack();
while(it.hasNext()) {
result.push(it.next());
}
assertThat(result, equalTo(intStack));
}
}