Create DepthFirstSearchTest.java

this test is created for the DepthFirstSearch.java file- that I added- containing the DepthFirstSearch algorithm

src/test/java/com/search/DepthFirstSearchTest.java

@@ -0,0 +1,36 @@
+package src.test.java.com.search;
+
+import org.junit.Assert;
+import org.junit.Test;
+import src.main.java.com.search.DepthFirstSearch;
+import src.main.java.com.search.BinaryTree;
+
+public class DepthFirstSearchTest {
+    @Test
+    public void testDepthFirstSearch() {
+
+        BinaryTree<Integer> tree1 = new BinaryTree<Integer>();
+        tree1.add(1,1);
+        tree1.add(2,2);
+        tree1.add(3,3);
+        tree1.add(4,4);
+        Assert.assertEquals("Incorrect index", 3, DepthFirstSearch.find(3, tree1));
+        Assert.assertEquals("Incorrect index", 1, DepthFirstSearch.find(1, tree1));
+        Assert.assertEquals("Incorrect index", null, DepthFirstSearch.find(0, tree1));
+        Assert.assertEquals("Incorrect index", null, DepthFirstSearch.find(8, tree1));
+        Assert.assertEquals("Incorrect index", null, DepthFirstSearch.find(-2, tree1));
+
+        BinaryTree<String> tree2 = new BinaryTree<String>();
+        tree2.add("1","A");
+        tree2.add("2","B");
+        tree2.add("3","C");
+        tree2.add("4","D");
+        
+        Assert.assertEquals("Incorrect index", "C", LinearSearch.findIndex(tree2,"3"));
+        Assert.assertEquals("Incorrect index", "B", LinearSearch.findIndex(tree2,"2"));
+        Assert.assertEquals("Incorrect index", null, LinearSearch.findIndex(tree2,"F"));
+
+        BinaryTree<String> tree3 = new BinaryTree<String>();
+        Assert.assertEquals("Incorrect index", null, LinearSearch.findIndex(tree3, ""));
+    }
+}