DepthFirstSearchTest.java

packagecom.thealgorithms.searches;

importstaticorg.junit.jupiter.api.Assertions.assertArrayEquals;
importstaticorg.junit.jupiter.api.Assertions.assertEquals;
importstaticorg.junit.jupiter.api.Assertions.assertTrue;

importcom.thealgorithms.datastructures.Node;
importjava.util.List;
importjava.util.Optional;
importorg.junit.jupiter.api.BeforeEach;
importorg.junit.jupiter.api.Test;

publicclassDepthFirstSearchTest {

privateNode<Integer> root;
privateDepthFirstSearch<Integer> dfs;

//
// Tree structure:
// 1
// / | \
// 2 3 4
// / \
// 5 6

@BeforeEach
publicvoidsetUp() {
// nodes declaration
root = newNode<>(1);

varnodeB = newNode<>(2);
varnodeC = newNode<>(3);
varnodeD = newNode<>(4);

varnodeE = newNode<>(5);
varnodeF = newNode<>(6);

// tree initialization
root.addChild(nodeB);
root.addChild(nodeC);
root.addChild(nodeD);

nodeB.addChild(nodeE);
nodeB.addChild(nodeF);

// create an instance to monitor the visited nodes
dfs = newDepthFirstSearch<>();
 }

@Test
publicvoidtestSearchRoot() {
IntegerexpectedValue = 1;
List<Integer> expectedPath = List.of(1);

// check value
Optional<Node<Integer>> value = dfs.recursiveSearch(root, expectedValue);
assertEquals(expectedValue, value.orElseGet(() -> newNode<>(null)).getValue());

// check path
assertArrayEquals(expectedPath.toArray(), dfs.getVisited().toArray());
 }

@Test
publicvoidtestSearch4() {
IntegerexpectedValue = 4;
List<Integer> expectedPath = List.of(1, 2, 5, 6, 3, 4);

// check value
Optional<Node<Integer>> value = dfs.recursiveSearch(root, expectedValue);
assertEquals(expectedValue, value.orElseGet(() -> newNode<>(null)).getValue());

// check path
assertArrayEquals(expectedPath.toArray(), dfs.getVisited().toArray());
 }

@Test
voidtestNullRoot() {
varvalue = dfs.recursiveSearch(null, 4);
assertTrue(value.isEmpty());
 }

@Test
voidtestSearchValueThatNotExists() {
List<Integer> expectedPath = List.of(1, 2, 5, 6, 3, 4);
varvalue = dfs.recursiveSearch(root, 10);

// check that the value is empty because it's not exists in the tree
assertTrue(value.isEmpty());

// check path is the whole list
assertArrayEquals(expectedPath.toArray(), dfs.getVisited().toArray());
 }
}