MaximumDepthOfBinaryTreeTest.java

import org.example.helpers.TreeNode;
import org.example.problems.maximum_depth_of_binary_tree.Solution;
import org.junit.jupiter.api.Assertions;
import org.junit.jupiter.params.ParameterizedTest;
import org.junit.jupiter.params.provider.Arguments;
import org.junit.jupiter.params.provider.MethodSource;
import java.util.stream.Stream;

public class MaximumDepthOfBinaryTreeTest {
 private static Stream<Arguments> provideCases() {
 return Stream.of(
 Arguments.of(new TreeNode(3, new TreeNode(9), new TreeNode(20, new TreeNode(15), new TreeNode(7))), 3),
 Arguments.of(new TreeNode(1, null, new TreeNode(2)), 2)
 );
 }

 @ParameterizedTest
 @MethodSource("provideCases")
 public void test(TreeNode source, int expected) {
 Solution s = new Solution();
 Assertions.assertSame(expected, s.maxDepth(source));
 }
}