refactor: DynamicArray (#5346)

This commit is contained in:
Alex Klymenko
2024-08-19 10:15:47 +02:00
committed by GitHub
parent 33fd79ad55
commit 04eae87512
2 changed files with 339 additions and 107 deletions

View File

@ -0,0 +1,255 @@
package com.thealgorithms.datastructures.dynamicarray;
import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertFalse;
import static org.junit.jupiter.api.Assertions.assertThrows;
import static org.junit.jupiter.api.Assertions.assertTrue;
import java.util.ConcurrentModificationException;
import java.util.Iterator;
import java.util.stream.Collectors;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
public class DynamicArrayTest {
private DynamicArray<String> array;
@BeforeEach
public void setUp() {
array = new DynamicArray<>();
}
@Test
public void testGetElement() {
array.add("Alice");
array.add("Bob");
assertEquals("Bob", array.get(1));
}
@Test
public void testGetInvalidIndex() {
assertThrows(IndexOutOfBoundsException.class, () -> array.get(-1));
assertThrows(IndexOutOfBoundsException.class, () -> array.get(10));
}
@Test
public void testAddElement() {
array.add("Alice");
array.add("Bob");
assertEquals(2, array.getSize());
assertEquals("Alice", array.get(0));
assertEquals("Bob", array.get(1));
}
@Test
public void testAddAndGet() {
array.add("Alice");
array.add("Bob");
assertEquals("Alice", array.get(0));
assertEquals("Bob", array.get(1));
assertThrows(IndexOutOfBoundsException.class, () -> array.get(2));
}
@Test
public void testAddBeyondCapacity() {
for (int i = 0; i < 20; i++) {
array.add("Element " + i);
}
assertEquals(20, array.getSize());
assertEquals("Element 19", array.get(19));
}
@Test
public void testPutElement() {
array.put(5, "Placeholder");
assertEquals(6, array.getSize());
assertEquals("Placeholder", array.get(5));
}
@Test
public void testPutElementBeyondCapacity() {
array.put(20, "FarAway");
assertEquals(21, array.getSize());
assertEquals("FarAway", array.get(20));
}
@Test
public void testPutAndDynamicCapacity() {
array.put(0, "Alice");
array.put(2, "Bob"); // Tests capacity expansion
assertEquals("Alice", array.get(0));
assertEquals("Bob", array.get(2));
assertEquals(3, array.getSize()); // Size should be 3 due to index 2
}
@Test
public void testRemoveElement() {
array.add("Alice");
array.add("Bob");
String removed = array.remove(0);
assertEquals("Alice", removed);
assertEquals(1, array.getSize());
assertEquals("Bob", array.get(0));
}
@Test
public void testRemoveInvalidIndex() {
assertThrows(IndexOutOfBoundsException.class, () -> array.remove(-1));
assertThrows(IndexOutOfBoundsException.class, () -> array.remove(10));
}
@Test
public void testRemoveComplex() {
array.add("Alice");
array.add("Bob");
array.add("Charlie");
assertEquals("Bob", array.remove(1));
assertEquals("Alice", array.get(0));
assertEquals("Charlie", array.get(1));
assertThrows(IndexOutOfBoundsException.class, () -> array.remove(2));
}
@Test
public void testRemoveEdgeCases() {
array.add("Alice");
array.add("Bob");
assertEquals("Alice", array.remove(0));
assertEquals(1, array.getSize());
assertEquals("Bob", array.get(0));
assertEquals("Bob", array.remove(0));
assertTrue(array.isEmpty());
assertThrows(IndexOutOfBoundsException.class, () -> array.get(0));
}
@Test
public void testIsEmpty() {
assertTrue(array.isEmpty());
array.add("Alice");
assertFalse(array.isEmpty());
array.remove(0);
assertTrue(array.isEmpty());
}
@Test
public void testSize() {
DynamicArray<String> array = new DynamicArray<>();
assertEquals(0, array.getSize());
array.add("Alice");
array.add("Bob");
assertEquals(2, array.getSize());
array.remove(0);
assertEquals(1, array.getSize());
}
@Test
public void testToString() {
array.add("Alice");
array.add("Bob");
assertEquals("[Alice, Bob]", array.toString());
}
@Test
public void testIterator() {
array.add("Alice");
array.add("Bob");
String result = array.stream().collect(Collectors.joining(", "));
assertEquals("Alice, Bob", result);
}
@Test
public void testStreamAsString() {
array.add("Alice");
array.add("Bob");
String result = array.stream().collect(Collectors.joining(", "));
assertEquals("Alice, Bob", result);
}
@Test
public void testStream() {
array.add("Alice");
array.add("Bob");
long count = array.stream().count();
assertEquals(2, count);
}
@Test
public void testAddToFullCapacity() {
DynamicArray<String> array = new DynamicArray<>(2);
array.add("Alice");
array.add("Bob");
array.add("Charlie"); // Triggers capacity expansion
assertEquals(3, array.getSize());
assertEquals("Charlie", array.get(2));
}
@Test
public void testPutWithNegativeIndex() {
assertThrows(IndexOutOfBoundsException.class, () -> array.put(-1, "Alice"));
}
@Test
public void testGetWithNegativeIndex() {
assertThrows(IndexOutOfBoundsException.class, () -> array.get(-1));
}
@Test
public void testIteratorConcurrentModification() {
array.add("Alice");
array.add("Bob");
Iterator<String> iterator = array.iterator();
array.add("Charlie"); // Modify during iteration
assertThrows(ConcurrentModificationException.class, iterator::next);
}
@Test
public void testIteratorRemove() {
array.add("Alice");
array.add("Bob");
Iterator<String> iterator = array.iterator();
assertEquals("Alice", iterator.next());
iterator.remove();
assertEquals(1, array.getSize());
assertEquals("Bob", array.get(0));
}
@Test
public void testRemoveBeyondCapacity() {
DynamicArray<String> array = new DynamicArray<>(2);
array.add("Alice");
array.add("Bob");
array.add("Charlie");
array.remove(1);
assertEquals(2, array.getSize());
assertEquals("Alice", array.get(0));
assertEquals("Charlie", array.get(1));
}
@Test
public void testCapacityDoubling() {
DynamicArray<String> array = new DynamicArray<>(1);
array.add("Alice");
array.add("Bob");
array.add("Charlie"); // Ensure capacity expansion is working
assertEquals(3, array.getSize());
assertEquals("Charlie", array.get(2));
}
}