tests/deque.test.js

   1 const { expect } = require('expect')
   2 const { Deque } = require('../lib/deque')
   3
   4 describe('Deque test suite', () => {
   5   it('Verify push() behavior', () => {
   6     const deque = new Deque()
   7     let rtSize = deque.push(1)
   8     expect(deque.size).toBe(1)
   9     expect(deque.maxSize).toBe(1)
  10     expect(rtSize).toBe(deque.size)
  11     expect(deque.head).toMatchObject({ data: 1 })
  12     expect(deque.tail).toMatchObject({ data: 1 })
  13     rtSize = deque.push(2)
  14     expect(deque.size).toBe(2)
  15     expect(deque.maxSize).toBe(2)
  16     expect(rtSize).toBe(deque.size)
  17     expect(deque.head).toMatchObject({ data: 1 })
  18     expect(deque.tail).toMatchObject({ data: 2 })
  19     rtSize = deque.push(3)
  20     expect(deque.size).toBe(3)
  21     expect(deque.maxSize).toBe(3)
  22     expect(rtSize).toBe(deque.size)
  23     expect(deque.head).toMatchObject({ data: 1 })
  24     expect(deque.tail).toMatchObject({ data: 3 })
  25   })
  26
  27   it('Verify unshift() behavior', () => {
  28     const deque = new Deque()
  29     let rtSize = deque.unshift(1)
  30     expect(deque.size).toBe(1)
  31     expect(deque.maxSize).toBe(1)
  32     expect(rtSize).toBe(deque.size)
  33     expect(deque.head).toMatchObject({ data: 1 })
  34     expect(deque.tail).toMatchObject({ data: 1 })
  35     rtSize = deque.unshift(2)
  36     expect(deque.size).toBe(2)
  37     expect(deque.maxSize).toBe(2)
  38     expect(rtSize).toBe(deque.size)
  39     expect(deque.head).toMatchObject({ data: 2 })
  40     expect(deque.tail).toMatchObject({ data: 1 })
  41     rtSize = deque.unshift(3)
  42     expect(deque.size).toBe(3)
  43     expect(deque.maxSize).toBe(3)
  44     expect(rtSize).toBe(deque.size)
  45     expect(deque.head).toMatchObject({ data: 3 })
  46     expect(deque.tail).toMatchObject({ data: 1 })
  47   })
  48
  49   it('Verify pop() behavior', () => {
  50     const deque = new Deque()
  51     deque.push(1)
  52     deque.push(2)
  53     deque.push(3)
  54     let rtItem = deque.pop()
  55     expect(deque.size).toBe(2)
  56     expect(deque.maxSize).toBe(3)
  57     expect(rtItem).toBe(3)
  58     expect(deque.head).toMatchObject({ data: 1 })
  59     expect(deque.tail).toMatchObject({ data: 2 })
  60     rtItem = deque.pop()
  61     expect(deque.size).toBe(1)
  62     expect(deque.maxSize).toBe(3)
  63     expect(rtItem).toBe(2)
  64     expect(deque.head).toMatchObject({ data: 1 })
  65     expect(deque.tail).toMatchObject({ data: 1 })
  66     rtItem = deque.pop()
  67     expect(deque.size).toBe(0)
  68     expect(deque.maxSize).toBe(3)
  69     expect(rtItem).toBe(1)
  70     expect(deque.head).toBeUndefined()
  71     expect(deque.tail).toBeUndefined()
  72   })
  73
  74   it('Verify shift() behavior', () => {
  75     const deque = new Deque()
  76     deque.push(1)
  77     deque.push(2)
  78     deque.push(3)
  79     let rtItem = deque.shift()
  80     expect(deque.size).toBe(2)
  81     expect(deque.maxSize).toBe(3)
  82     expect(rtItem).toBe(1)
  83     expect(deque.head).toMatchObject({ data: 2 })
  84     expect(deque.tail).toMatchObject({ data: 3 })
  85     rtItem = deque.shift()
  86     expect(deque.size).toBe(1)
  87     expect(deque.maxSize).toBe(3)
  88     expect(rtItem).toBe(2)
  89     expect(deque.head).toMatchObject({ data: 3 })
  90     expect(deque.tail).toMatchObject({ data: 3 })
  91     rtItem = deque.shift()
  92     expect(deque.size).toBe(0)
  93     expect(deque.maxSize).toBe(3)
  94     expect(rtItem).toBe(3)
  95     expect(deque.head).toBeUndefined()
  96     expect(deque.tail).toBeUndefined()
  97   })
  98
  99   it('Verify peekFirst() behavior', () => {
 100     const deque = new Deque()
 101     deque.push(1)
 102     deque.push(2)
 103     deque.push(3)
 104     expect(deque.size).toBe(3)
 105     expect(deque.peekFirst()).toBe(1)
 106     expect(deque.size).toBe(3)
 107   })
 108
 109   it('Verify peekLast() behavior', () => {
 110     const deque = new Deque()
 111     deque.push(1)
 112     deque.push(2)
 113     deque.push(3)
 114     expect(deque.size).toBe(3)
 115     expect(deque.peekLast()).toBe(3)
 116     expect(deque.size).toBe(3)
 117   })
 118
 119   it('Verify clear() behavior', () => {
 120     const deque = new Deque()
 121     deque.push(1)
 122     deque.push(2)
 123     deque.push(3)
 124     expect(deque.size).toBe(3)
 125     expect(deque.maxSize).toBe(3)
 126     expect(deque.head).toMatchObject({ data: 1 })
 127     expect(deque.tail).toMatchObject({ data: 3 })
 128     deque.clear()
 129     expect(deque.size).toBe(0)
 130     expect(deque.maxSize).toBe(0)
 131     expect(deque.head).toBeUndefined()
 132     expect(deque.tail).toBeUndefined()
 133   })
 134
 135   it('Verify iterator behavior', () => {
 136     const deque = new Deque()
 137     deque.push(1)
 138     deque.push(2)
 139     deque.push(3)
 140     let i = 1
 141     for (const value of deque) {
 142       expect(value).toBe(i)
 143       ++i
 144     }
 145   })
 146
 147   it('Verify backward() iterator behavior', () => {
 148     const deque = new Deque()
 149     deque.push(1)
 150     deque.push(2)
 151     deque.push(3)
 152     let i = deque.size
 153     for (const value of deque.backward()) {
 154       expect(value).toBe(i)
 155       --i
 156     }
 157   })
 158 })