dist-javascript-algorithms-and-data-structures/dist/data-structures/graph/__test__/GraphVertex.test.js

Algorithms and data-structures implemented on JavaScript

"use strict";

var _GraphVertex = _interopRequireDefault(require("../GraphVertex"));

var _GraphEdge = _interopRequireDefault(require("../GraphEdge"));

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

describe('GraphVertex', () => {
  it('should throw an error when trying to create vertex without value', () => {
    let vertex = null;

    function createEmptyVertex() {
      vertex = new _GraphVertex.default();
    }

    expect(vertex).toBeNull();
    expect(createEmptyVertex).toThrow();
  });
  it('should create graph vertex', () => {
    const vertex = new _GraphVertex.default('A');
    expect(vertex).toBeDefined();
    expect(vertex.value).toBe('A');
    expect(vertex.toString()).toBe('A');
    expect(vertex.getKey()).toBe('A');
    expect(vertex.edges.toString()).toBe('');
    expect(vertex.getEdges()).toEqual([]);
  });
  it('should add edges to vertex and check if it exists', () => {
    const vertexA = new _GraphVertex.default('A');
    const vertexB = new _GraphVertex.default('B');
    const edgeAB = new _GraphEdge.default(vertexA, vertexB);
    vertexA.addEdge(edgeAB);
    expect(vertexA.hasEdge(edgeAB)).toBe(true);
    expect(vertexB.hasEdge(edgeAB)).toBe(false);
    expect(vertexA.getEdges().length).toBe(1);
    expect(vertexA.getEdges()[0].toString()).toBe('A_B');
  });
  it('should delete edges from vertex', () => {
    const vertexA = new _GraphVertex.default('A');
    const vertexB = new _GraphVertex.default('B');
    const vertexC = new _GraphVertex.default('C');
    const edgeAB = new _GraphEdge.default(vertexA, vertexB);
    const edgeAC = new _GraphEdge.default(vertexA, vertexC);
    vertexA.addEdge(edgeAB).addEdge(edgeAC);
    expect(vertexA.hasEdge(edgeAB)).toBe(true);
    expect(vertexB.hasEdge(edgeAB)).toBe(false);
    expect(vertexA.hasEdge(edgeAC)).toBe(true);
    expect(vertexC.hasEdge(edgeAC)).toBe(false);
    expect(vertexA.getEdges().length).toBe(2);
    expect(vertexA.getEdges()[0].toString()).toBe('A_B');
    expect(vertexA.getEdges()[1].toString()).toBe('A_C');
    vertexA.deleteEdge(edgeAB);
    expect(vertexA.hasEdge(edgeAB)).toBe(false);
    expect(vertexA.hasEdge(edgeAC)).toBe(true);
    expect(vertexA.getEdges()[0].toString()).toBe('A_C');
    vertexA.deleteEdge(edgeAC);
    expect(vertexA.hasEdge(edgeAB)).toBe(false);
    expect(vertexA.hasEdge(edgeAC)).toBe(false);
    expect(vertexA.getEdges().length).toBe(0);
  });
  it('should delete all edges from vertex', () => {
    const vertexA = new _GraphVertex.default('A');
    const vertexB = new _GraphVertex.default('B');
    const vertexC = new _GraphVertex.default('C');
    const edgeAB = new _GraphEdge.default(vertexA, vertexB);
    const edgeAC = new _GraphEdge.default(vertexA, vertexC);
    vertexA.addEdge(edgeAB).addEdge(edgeAC);
    expect(vertexA.hasEdge(edgeAB)).toBe(true);
    expect(vertexB.hasEdge(edgeAB)).toBe(false);
    expect(vertexA.hasEdge(edgeAC)).toBe(true);
    expect(vertexC.hasEdge(edgeAC)).toBe(false);
    expect(vertexA.getEdges().length).toBe(2);
    vertexA.deleteAllEdges();
    expect(vertexA.hasEdge(edgeAB)).toBe(false);
    expect(vertexB.hasEdge(edgeAB)).toBe(false);
    expect(vertexA.hasEdge(edgeAC)).toBe(false);
    expect(vertexC.hasEdge(edgeAC)).toBe(false);
    expect(vertexA.getEdges().length).toBe(0);
  });
  it('should return vertex neighbors in case if current node is start one', () => {
    const vertexA = new _GraphVertex.default('A');
    const vertexB = new _GraphVertex.default('B');
    const vertexC = new _GraphVertex.default('C');
    const edgeAB = new _GraphEdge.default(vertexA, vertexB);
    const edgeAC = new _GraphEdge.default(vertexA, vertexC);
    vertexA.addEdge(edgeAB).addEdge(edgeAC);
    expect(vertexB.getNeighbors()).toEqual([]);
    const neighbors = vertexA.getNeighbors();
    expect(neighbors.length).toBe(2);
    expect(neighbors[0]).toEqual(vertexB);
    expect(neighbors[1]).toEqual(vertexC);
  });
  it('should return vertex neighbors in case if current node is end one', () => {
    const vertexA = new _GraphVertex.default('A');
    const vertexB = new _GraphVertex.default('B');
    const vertexC = new _GraphVertex.default('C');
    const edgeBA = new _GraphEdge.default(vertexB, vertexA);
    const edgeCA = new _GraphEdge.default(vertexC, vertexA);
    vertexA.addEdge(edgeBA).addEdge(edgeCA);
    expect(vertexB.getNeighbors()).toEqual([]);
    const neighbors = vertexA.getNeighbors();
    expect(neighbors.length).toBe(2);
    expect(neighbors[0]).toEqual(vertexB);
    expect(neighbors[1]).toEqual(vertexC);
  });
  it('should check if vertex has specific neighbor', () => {
    const vertexA = new _GraphVertex.default('A');
    const vertexB = new _GraphVertex.default('B');
    const vertexC = new _GraphVertex.default('C');
    const edgeAB = new _GraphEdge.default(vertexA, vertexB);
    vertexA.addEdge(edgeAB);
    expect(vertexA.hasNeighbor(vertexB)).toBe(true);
    expect(vertexA.hasNeighbor(vertexC)).toBe(false);
  });
  it('should edge by vertex', () => {
    const vertexA = new _GraphVertex.default('A');
    const vertexB = new _GraphVertex.default('B');
    const vertexC = new _GraphVertex.default('C');
    const edgeAB = new _GraphEdge.default(vertexA, vertexB);
    vertexA.addEdge(edgeAB);
    expect(vertexA.findEdge(vertexB)).toEqual(edgeAB);
    expect(vertexA.findEdge(vertexC)).toBeNull();
  });
  it('should calculate vertex degree', () => {
    const vertexA = new _GraphVertex.default('A');
    const vertexB = new _GraphVertex.default('B');
    expect(vertexA.getDegree()).toBe(0);
    const edgeAB = new _GraphEdge.default(vertexA, vertexB);
    vertexA.addEdge(edgeAB);
    expect(vertexA.getDegree()).toBe(1);
    const edgeBA = new _GraphEdge.default(vertexB, vertexA);
    vertexA.addEdge(edgeBA);
    expect(vertexA.getDegree()).toBe(2);
    vertexA.addEdge(edgeAB);
    expect(vertexA.getDegree()).toBe(3);
    expect(vertexA.getEdges().length).toEqual(3);
  });
});