dist-javascript-algorithms-and-data-structures/dist/algorithms/tree/depth-first-search/__test__/depthFirstSearch.test.js

Algorithms and data-structures implemented on JavaScript

"use strict";

var _BinaryTreeNode = _interopRequireDefault(require("../../../../data-structures/tree/BinaryTreeNode"));

var _depthFirstSearch = _interopRequireDefault(require("../depthFirstSearch"));

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

describe('depthFirstSearch', () => {
  it('should perform DFS operation on tree', () => {
    const nodeA = new _BinaryTreeNode.default('A');
    const nodeB = new _BinaryTreeNode.default('B');
    const nodeC = new _BinaryTreeNode.default('C');
    const nodeD = new _BinaryTreeNode.default('D');
    const nodeE = new _BinaryTreeNode.default('E');
    const nodeF = new _BinaryTreeNode.default('F');
    const nodeG = new _BinaryTreeNode.default('G');
    nodeA.setLeft(nodeB).setRight(nodeC);
    nodeB.setLeft(nodeD).setRight(nodeE);
    nodeC.setLeft(nodeF).setRight(nodeG); // In-order traversing.

    expect(nodeA.toString()).toBe('D,B,E,A,F,C,G');
    const enterNodeCallback = jest.fn();
    const leaveNodeCallback = jest.fn(); // Traverse tree without callbacks first to check default ones.

    (0, _depthFirstSearch.default)(nodeA); // Traverse tree with callbacks.

    (0, _depthFirstSearch.default)(nodeA, {
      enterNode: enterNodeCallback,
      leaveNode: leaveNodeCallback
    });
    expect(enterNodeCallback).toHaveBeenCalledTimes(7);
    expect(leaveNodeCallback).toHaveBeenCalledTimes(7); // Check node entering.

    expect(enterNodeCallback.mock.calls[0][0].value).toEqual('A');
    expect(enterNodeCallback.mock.calls[1][0].value).toEqual('B');
    expect(enterNodeCallback.mock.calls[2][0].value).toEqual('D');
    expect(enterNodeCallback.mock.calls[3][0].value).toEqual('E');
    expect(enterNodeCallback.mock.calls[4][0].value).toEqual('C');
    expect(enterNodeCallback.mock.calls[5][0].value).toEqual('F');
    expect(enterNodeCallback.mock.calls[6][0].value).toEqual('G'); // Check node leaving.

    expect(leaveNodeCallback.mock.calls[0][0].value).toEqual('D');
    expect(leaveNodeCallback.mock.calls[1][0].value).toEqual('E');
    expect(leaveNodeCallback.mock.calls[2][0].value).toEqual('B');
    expect(leaveNodeCallback.mock.calls[3][0].value).toEqual('F');
    expect(leaveNodeCallback.mock.calls[4][0].value).toEqual('G');
    expect(leaveNodeCallback.mock.calls[5][0].value).toEqual('C');
    expect(leaveNodeCallback.mock.calls[6][0].value).toEqual('A');
  });
  it('allow users to redefine node visiting logic', () => {
    const nodeA = new _BinaryTreeNode.default('A');
    const nodeB = new _BinaryTreeNode.default('B');
    const nodeC = new _BinaryTreeNode.default('C');
    const nodeD = new _BinaryTreeNode.default('D');
    const nodeE = new _BinaryTreeNode.default('E');
    const nodeF = new _BinaryTreeNode.default('F');
    const nodeG = new _BinaryTreeNode.default('G');
    nodeA.setLeft(nodeB).setRight(nodeC);
    nodeB.setLeft(nodeD).setRight(nodeE);
    nodeC.setLeft(nodeF).setRight(nodeG); // In-order traversing.

    expect(nodeA.toString()).toBe('D,B,E,A,F,C,G');
    const enterNodeCallback = jest.fn();
    const leaveNodeCallback = jest.fn(); // Traverse tree without callbacks first to check default ones.

    (0, _depthFirstSearch.default)(nodeA); // Traverse tree with callbacks.

    (0, _depthFirstSearch.default)(nodeA, {
      allowTraversal: (node, child) => {
        // Forbid traversing left part of the tree.
        return child.value !== 'B';
      },
      enterNode: enterNodeCallback,
      leaveNode: leaveNodeCallback
    });
    expect(enterNodeCallback).toHaveBeenCalledTimes(4);
    expect(leaveNodeCallback).toHaveBeenCalledTimes(4); // Check node entering.

    expect(enterNodeCallback.mock.calls[0][0].value).toEqual('A');
    expect(enterNodeCallback.mock.calls[1][0].value).toEqual('C');
    expect(enterNodeCallback.mock.calls[2][0].value).toEqual('F');
    expect(enterNodeCallback.mock.calls[3][0].value).toEqual('G'); // Check node leaving.

    expect(leaveNodeCallback.mock.calls[0][0].value).toEqual('F');
    expect(leaveNodeCallback.mock.calls[1][0].value).toEqual('G');
    expect(leaveNodeCallback.mock.calls[2][0].value).toEqual('C');
    expect(leaveNodeCallback.mock.calls[3][0].value).toEqual('A');
  });
});