test cases added to test_list_to_tree.py and also tested

tests/non-linear/trees/binary_search_tree/test_list_to_tree.py

@@ -1 +1,71 @@
+import pytest
 from datastructpy.non_linear.trees.binary_search_tree import BinarySearchTree
+
+# Fixture to create a Binary Search Tree (BST) with predefined values
+@pytest.mark.parametrize("elements, expected_root, expected_left, expected_right", [
+    ([10, 5, 15, 12, 20], 10, 5, 15),  
+    ([30, 20, 40, 35, 50], 30, 20, 40),  
+])
+
+# Test Case 1: Valid Input (Standard Case)
+def test_list_to_tree_valid_input(elements, expected_root, expected_left, expected_right):
+    """
+    Test case to check if a Binary Search Tree (BST) is correctly created 
+    from a list of elements.
+    """
+    bst = BinarySearchTree.list_to_tree(elements)
+
+    # Test the root node and its immediate children
+    assert bst.root.key == expected_root, f"Expected root key to be {expected_root}, but got {bst.root.key}"
+    assert bst.root.left.key == expected_left, f"Expected left child to be {expected_left}, but got {bst.root.left.key}"
+    assert bst.root.right.key == expected_right, f"Expected right child to be {expected_right}, but got {bst.root.right.key}"
+
+    print("Test passed: Valid input")
+
+#Test Case 2: Input is Not a List
+def test_list_to_tree_not_a_list():
+    try:
+        bst = BinarySearchTree.list_to_tree(10)  
+    except ValueError as e:
+        assert str(e) == "Input must be a list of integers.", f"Expected error message, but got {e}"
+
+    print("Test passed: Input is not a list")
+
+#Test Case 3: List Contains Non-Integer Elements
+def test_list_to_tree_non_integer_elements():
+    try:
+        bst = BinarySearchTree.list_to_tree([10, "5", 15]) 
+    except ValueError as e:
+        assert str(e) == "All elements in the list must be integers.", f"Expected error message, but got {e}"
+
+    print("Test passed: List contains non-integer elements")
+
+
+#Test Case 4: Empty List
+def test_list_to_tree_empty_list():
+    elements = []
+    bst = BinarySearchTree.list_to_tree(elements)
+    assert bst.root is None, f"Expected root to be None, but got {bst.root}"
+
+    print("Test passed: Empty list")
+
+
+
+#Test Case 5: List with One Element
+def test_list_to_tree_single_element():
+    elements = [10]
+    bst = BinarySearchTree.list_to_tree(elements)
+    assert bst.root.key == 10, f"Expected root key to be 10, but got {bst.root.key}"
+
+    print("Test passed: Single element list")
+
+#Test Case 6: List with Negative Numbers
+def test_list_to_tree_negative_numbers():
+    elements = [-10, -5, -15, -12, -20]
+    bst = BinarySearchTree.list_to_tree(elements)
+    assert bst.root.key == -10, f"Expected root key to be -10, but got {bst.root.key}"
+    assert bst.root.left.key == -15, f"Expected left child to be -15, but got {bst.root.left.key}"
+    assert bst.root.right.key == -5, f"Expected right child to be -5, but got {bst.root.right.key}"
+
+    print("Test passed: List with negative numbers")
+