tests/circular-buffer.test.mjs

   1 import { expect } from 'expect'
   2
   3 import { CircularBuffer, defaultBufferSize } from '../lib/circular-buffer.cjs'
   4
   5 describe('Circular buffer test suite', t => {
   6   it('Verify that circular buffer can be instantiated', () => {
   7     const circularBuffer = new CircularBuffer()
   8     expect(circularBuffer).toBeInstanceOf(CircularBuffer)
   9     expect(circularBuffer.readIdx).toBe(0)
  10     expect(circularBuffer.writeIdx).toBe(0)
  11     expect(circularBuffer.maxArrayIdx).toBe(defaultBufferSize - 1)
  12     expect(circularBuffer.size).toBe(0)
  13     expect(circularBuffer.items).toBeInstanceOf(Array)
  14     expect(circularBuffer.items.length).toBe(defaultBufferSize)
  15   })
  16
  17   it('Verify that circular buffer size can be set at instance creation', () => {
  18     const size = 1000
  19     const circularBuffer = new CircularBuffer(size)
  20     expect(circularBuffer.maxArrayIdx).toBe(size - 1)
  21     expect(circularBuffer.items).toBeInstanceOf(Array)
  22     expect(circularBuffer.items.length).toBe(size)
  23   })
  24
  25   it('Verify that circular buffer size is valid at instance creation', () => {
  26     expect(() => new CircularBuffer(0.25)).toThrow(
  27       new TypeError('Invalid circular buffer size: 0.25 is not an integer')
  28     )
  29     expect(() => new CircularBuffer(-1)).toThrow(
  30       new RangeError('Invalid circular buffer size: -1 < 0')
  31     )
  32     expect(() => new CircularBuffer(Number.MAX_SAFE_INTEGER + 1)).toThrow(
  33       new TypeError(
  34         `Invalid circular buffer size: ${
  35           Number.MAX_SAFE_INTEGER + 1
  36         } is not an integer`
  37       )
  38     )
  39   })
  40
  41   it('Verify that circular buffer put() works as intended', () => {
  42     const circularBuffer = new CircularBuffer(4)
  43     circularBuffer.put(1)
  44     expect(circularBuffer.items).toMatchObject([1])
  45     expect(circularBuffer.writeIdx).toBe(1)
  46     expect(circularBuffer.size).toBe(1)
  47     circularBuffer.put(2)
  48     expect(circularBuffer.items).toMatchObject([1, 2])
  49     expect(circularBuffer.writeIdx).toBe(2)
  50     expect(circularBuffer.size).toBe(2)
  51     circularBuffer.put(3)
  52     expect(circularBuffer.items).toMatchObject([1, 2, 3])
  53     expect(circularBuffer.writeIdx).toBe(3)
  54     expect(circularBuffer.size).toBe(3)
  55     circularBuffer.put(4)
  56     expect(circularBuffer.items).toMatchObject([1, 2, 3, 4])
  57     expect(circularBuffer.writeIdx).toBe(0)
  58     expect(circularBuffer.size).toBe(4)
  59     circularBuffer.put(5)
  60     expect(circularBuffer.items).toMatchObject([5, 2, 3, 4])
  61     expect(circularBuffer.writeIdx).toBe(1)
  62     expect(circularBuffer.size).toBe(4)
  63     circularBuffer.put(6)
  64     expect(circularBuffer.items).toMatchObject([5, 6, 3, 4])
  65     expect(circularBuffer.writeIdx).toBe(2)
  66     expect(circularBuffer.size).toBe(4)
  67   })
  68
  69   it('Verify that circular buffer get() works as intended', () => {
  70     const circularBuffer = new CircularBuffer(4)
  71     circularBuffer.put(1)
  72     circularBuffer.put(2)
  73     circularBuffer.put(3)
  74     circularBuffer.put(4)
  75     expect(circularBuffer.get()).toBe(1)
  76     expect(circularBuffer.readIdx).toBe(1)
  77     expect(circularBuffer.size).toBe(3)
  78     expect(circularBuffer.get()).toBe(2)
  79     expect(circularBuffer.readIdx).toBe(2)
  80     expect(circularBuffer.size).toBe(2)
  81     circularBuffer.put(5)
  82     circularBuffer.put(6)
  83     expect(circularBuffer.get()).toBe(3)
  84     expect(circularBuffer.readIdx).toBe(3)
  85     expect(circularBuffer.size).toBe(3)
  86     expect(circularBuffer.get()).toBe(4)
  87     expect(circularBuffer.readIdx).toBe(0)
  88     expect(circularBuffer.size).toBe(2)
  89     expect(circularBuffer.get()).toBe(5)
  90     expect(circularBuffer.readIdx).toBe(1)
  91     expect(circularBuffer.size).toBe(1)
  92     expect(circularBuffer.get()).toBe(6)
  93     expect(circularBuffer.readIdx).toBe(2)
  94     expect(circularBuffer.size).toBe(0)
  95     expect(circularBuffer.get()).toBe(undefined)
  96     expect(circularBuffer.readIdx).toBe(2)
  97     expect(circularBuffer.size).toBe(0)
  98   })
  99
 100   it('Verify that circular buffer empty() works as intended', () => {
 101     const circularBuffer = new CircularBuffer(4)
 102     expect(circularBuffer.empty()).toBe(true)
 103     circularBuffer.put(1)
 104     expect(circularBuffer.empty()).toBe(false)
 105     circularBuffer.put(2)
 106     expect(circularBuffer.empty()).toBe(false)
 107     circularBuffer.put(3)
 108     expect(circularBuffer.empty()).toBe(false)
 109     circularBuffer.put(4)
 110     expect(circularBuffer.empty()).toBe(false)
 111     circularBuffer.get()
 112     expect(circularBuffer.empty()).toBe(false)
 113     circularBuffer.get()
 114     expect(circularBuffer.empty()).toBe(false)
 115     circularBuffer.get()
 116     expect(circularBuffer.empty()).toBe(false)
 117     circularBuffer.get()
 118     expect(circularBuffer.empty()).toBe(true)
 119   })
 120
 121   it('Verify that circular buffer full() works as intended', () => {
 122     const circularBuffer = new CircularBuffer(4)
 123     expect(circularBuffer.full()).toBe(false)
 124     circularBuffer.put(1)
 125     expect(circularBuffer.full()).toBe(false)
 126     circularBuffer.put(2)
 127     expect(circularBuffer.full()).toBe(false)
 128     circularBuffer.put(3)
 129     expect(circularBuffer.full()).toBe(false)
 130     circularBuffer.put(4)
 131     expect(circularBuffer.full()).toBe(true)
 132     circularBuffer.get()
 133     expect(circularBuffer.full()).toBe(false)
 134     circularBuffer.put(5)
 135     expect(circularBuffer.full()).toBe(true)
 136     circularBuffer.get()
 137     expect(circularBuffer.full()).toBe(false)
 138     circularBuffer.get()
 139     expect(circularBuffer.full()).toBe(false)
 140     circularBuffer.get()
 141     expect(circularBuffer.full()).toBe(false)
 142     circularBuffer.get()
 143     expect(circularBuffer.full()).toBe(false)
 144     expect(circularBuffer.empty()).toBe(true)
 145   })
 146
 147   it('Verify that circular buffer toArray() works as intended', () => {
 148     const circularBuffer = new CircularBuffer(4)
 149     circularBuffer.put(1)
 150     circularBuffer.put(2)
 151     circularBuffer.put(3)
 152     circularBuffer.put(4)
 153     circularBuffer.put(5)
 154     circularBuffer.put(6)
 155     expect(circularBuffer.toArray()).toStrictEqual([5, 6, 3, 4])
 156   })
 157 })