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.items).toBeInstanceOf(Array)
  13     expect(circularBuffer.items.length).toBe(defaultBufferSize)
  14   })
  15
  16   it('Verify that circular buffer size can be set at instance creation', () => {
  17     const circularBuffer = new CircularBuffer(1000)
  18     expect(circularBuffer.maxArrayIdx).toBe(999)
  19     expect(circularBuffer.items).toBeInstanceOf(Array)
  20     expect(circularBuffer.items.length).toBe(1000)
  21   })
  22
  23   it('Verify that circular buffer size is valid at instance creation', () => {
  24     expect(() => new CircularBuffer(0.25)).toThrow(
  25       new TypeError('Invalid circular buffer size: 0.25 is not an integer')
  26     )
  27     expect(() => new CircularBuffer(-1)).toThrow(
  28       new RangeError('Invalid circular buffer size: -1 < 0')
  29     )
  30     expect(() => new CircularBuffer(Number.MAX_SAFE_INTEGER + 1)).toThrow(
  31       new TypeError(
  32         `Invalid circular buffer size: ${
  33           Number.MAX_SAFE_INTEGER + 1
  34         } is not an integer`
  35       )
  36     )
  37   })
  38
  39   it('Verify that circular buffer put() works as intended', () => {
  40     const circularBuffer = new CircularBuffer(4)
  41     circularBuffer.put(1)
  42     expect(circularBuffer.items).toMatchObject([1])
  43     expect(circularBuffer.writeIdx).toBe(1)
  44     circularBuffer.put(2)
  45     expect(circularBuffer.items).toMatchObject([1, 2])
  46     expect(circularBuffer.writeIdx).toBe(2)
  47     circularBuffer.put(3)
  48     expect(circularBuffer.items).toMatchObject([1, 2, 3])
  49     expect(circularBuffer.writeIdx).toBe(3)
  50     circularBuffer.put(4)
  51     expect(circularBuffer.items).toMatchObject([1, 2, 3, 4])
  52     expect(circularBuffer.writeIdx).toBe(0)
  53     circularBuffer.put(5)
  54     expect(circularBuffer.items).toMatchObject([5, 2, 3, 4])
  55     expect(circularBuffer.writeIdx).toBe(1)
  56     circularBuffer.put(6)
  57     expect(circularBuffer.items).toMatchObject([5, 6, 3, 4])
  58     expect(circularBuffer.writeIdx).toBe(2)
  59   })
  60
  61   it('Verify that circular buffer toArray() works as intended', () => {
  62     const circularBuffer = new CircularBuffer(4)
  63     circularBuffer.put(1)
  64     circularBuffer.put(2)
  65     circularBuffer.put(3)
  66     circularBuffer.put(4)
  67     circularBuffer.put(5)
  68     circularBuffer.put(6)
  69     expect(circularBuffer.toArray()).toStrictEqual([5, 6, 3, 4])
  70   })
  71 })