rpn-infix-postfix/spec/stack.spec.js

RPN infix to posfix

const { Stack } = require('../src');

describe('Stack class', function () {
  let stack;
  beforeEach(function () {
    stack = new Stack(5);
  });

  describe('[Method] push', function () {
    it('should push items into stack', function () {
      expect(stack.isEmpty()).toBe(true);
      stack.push(1);
      expect(stack.isEmpty()).toBe(false);
    });
    it('should throw error if stack is allready full', function () {
      expect(stack.isEmpty()).toBe(true);
      stack.push(1);
      stack.push(1);
      stack.push(1);
      stack.push(1);
      stack.push(1);
      expect(function () { stack.push(1); }).toThrow();
    });
  });

  describe('[Method] pop', function () {
    it('should give the last element added to stack', function () {
      stack.push(1);
      stack.push(2);
      expect(stack.pop()).toBe(2);
      expect(stack.pop()).toBe(1);
    });
    it('should throw error if stack is empty', function () {
      stack.push(1);
      stack.pop();
      expect(function () { stack.pop() }).toThrow();
    });
  });
});