diff --git a/src/_DataStructures_/Trees/BinarySearchTree/bst-deletion.test.js b/src/_DataStructures_/Trees/BinarySearchTree/bst-deletion.test.js new file mode 100644 index 00000000..2b7f2b3e --- /dev/null +++ b/src/_DataStructures_/Trees/BinarySearchTree/bst-deletion.test.js @@ -0,0 +1,51 @@ +const BinarySearchTree = require('./index'); +const heightOfBST = require('./height-of-bst/index'); + +describe('Binary search tree traversals', () => { + let bst; + + describe('Creates BST', () => { + it('should create BST', () => { + // Creates BST + bst = new BinarySearchTree(6); + bst.add(4); + bst.add(9); + bst.add(2); + bst.add(5); + bst.add(8); + bst.add(12); + }); + }); + + describe('Check bst was created as expected', () => { + it('Inorder traversal of the created bst should be [ 2, 4, 5, 6, 8, 9, 12 ]', () => { + expect(bst.traverseInorder()).toEqual([2, 4, 5, 6, 8, 9, 12]); + }); + + it('Preorder traversal of the created bst should be [ 6, 4, 2, 5, 9, 8, 12 ]', () => { + expect(bst.traversePreorder()).toEqual([6, 4, 2, 5, 9, 8, 12]); + }); + + it('Postorder traversal of the created bst should be [ 2, 5, 4, 8, 12, 9, 6 ]', () => { + expect(bst.traversePostorder()).toEqual([2, 5, 4, 8, 12, 9, 6]); + }); + }); + + describe('BST node deletions', () => { + it('should check height of bst to be 3 prior deletion', () => { + expect(heightOfBST(bst.root)).toEqual(3); + }); + + it('deleting leaf element does not affect tree height if it has sibling', () => { + bst.remove(2); + bst.remove(8); + expect(heightOfBST(bst.root)).toEqual(3); + }); + + it('deleting leaf element does affect tree height if it has no-sibling', () => { + bst.remove(5); + bst.remove(12); + expect(heightOfBST(bst.root)).toEqual(2); + }); + }); +});