dist-javascript-algorithms-and-data-structures/dist/data-structures/stack/__test__/Stack.test.js

Algorithms and data-structures implemented on JavaScript

"use strict";

var _Stack = _interopRequireDefault(require("../Stack"));

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

describe('Stack', () => {
  it('should create empty stack', () => {
    const stack = new _Stack.default();
    expect(stack).not.toBeNull();
    expect(stack.linkedList).not.toBeNull();
  });
  it('should stack data to stack', () => {
    const stack = new _Stack.default();
    stack.push(1);
    stack.push(2);
    expect(stack.toString()).toBe('2,1');
  });
  it('should peek data from stack', () => {
    const stack = new _Stack.default();
    expect(stack.peek()).toBeNull();
    stack.push(1);
    stack.push(2);
    expect(stack.peek()).toBe(2);
    expect(stack.peek()).toBe(2);
  });
  it('should check if stack is empty', () => {
    const stack = new _Stack.default();
    expect(stack.isEmpty()).toBe(true);
    stack.push(1);
    expect(stack.isEmpty()).toBe(false);
  });
  it('should pop data from stack', () => {
    const stack = new _Stack.default();
    stack.push(1);
    stack.push(2);
    expect(stack.pop()).toBe(2);
    expect(stack.pop()).toBe(1);
    expect(stack.pop()).toBeNull();
    expect(stack.isEmpty()).toBe(true);
  });
  it('should be possible to push/pop objects', () => {
    const stack = new _Stack.default();
    stack.push({
      value: 'test1',
      key: 'key1'
    });
    stack.push({
      value: 'test2',
      key: 'key2'
    });

    const stringifier = value => `${value.key}:${value.value}`;

    expect(stack.toString(stringifier)).toBe('key2:test2,key1:test1');
    expect(stack.pop().value).toBe('test2');
    expect(stack.pop().value).toBe('test1');
  });
  it('should be possible to convert stack to array', () => {
    const stack = new _Stack.default();
    expect(stack.peek()).toBeNull();
    stack.push(1);
    stack.push(2);
    stack.push(3);
    expect(stack.toArray()).toEqual([3, 2, 1]);
  });
});