import { BufferReader } from '../src/buffer-reader'

test('Read a UInt16.', () => {
  // Given
  const buffer = Buffer.from([0x30, 0x39])

  // When
  const smartBuffer = new BufferReader(buffer)

  // Then
  expect(smartBuffer.readUInt16()).toBe(12345)
})

test('Read a UInt32.', () => {
  // Given
  const buffer = Buffer.from([0x49, 0x96, 0x02, 0xD2])

  // When
  const smartBuffer = new BufferReader(buffer)

  // Then
  expect(smartBuffer.readUInt32()).toBe(1234567890)
})

test('Read a buffer.', () => {
  // Given
  const buffer = Buffer.from([0, 1, 2, 3, 4, 5, 6, 7, 8, 9])

  // When
  const smartBuffer = new BufferReader(buffer)

  // Then
  expect(smartBuffer.readBuffer(4)).toMatchObject(Buffer.from([0, 1, 2, 3]))
})

test('Cursor is correctly incremented after reading a UInt16.', () => {
  // Given
  const buffer = Buffer.from([0x30, 0x39, 0x1A, 0x85])

  // When
  const smartBuffer = new BufferReader(buffer)

  // Then
  expect(smartBuffer.readUInt16()).toBe(12345)
  expect(smartBuffer.readUInt16()).toBe(6789)
})

test('Cursor is correctly incremented after reading a buffer.', () => {
  // Given
  const buffer = Buffer.from([0, 1, 2, 3, 4, 5, 6, 7, 8, 9])

  // When
  const smartBuffer = new BufferReader(buffer)

  // Then
  expect(smartBuffer.readBuffer(4)).toMatchObject(Buffer.from([0, 1, 2, 3]))
  expect(smartBuffer.readBuffer(4)).toMatchObject(Buffer.from([4, 5, 6, 7]))
})

test('Cursor is correctly incremented after reading a UInt32.', () => {
  // Given
  const buffer = Buffer.from([0x49, 0x96, 0x02, 0xD2, 0x3A, 0xDE, 0x68, 0xB1])

  // When
  const smartBuffer = new BufferReader(buffer)

  // Then
  expect(smartBuffer.readUInt32()).toBe(1234567890)
  expect(smartBuffer.readUInt32()).toBe(987654321)
})

test('Seek to position below 0 throws range error.', () => {
  // Given
  const buffer = Buffer.from([])

  // When
  const smartBuffer = new BufferReader(buffer)

  // Then
  expect(() => {
    smartBuffer.cursor = -1
  }).toThrow(RangeError)
})

test('Seek beyond buffer throws range error.', () => {
  // Given
  const buffer = Buffer.from([0, 1, 2, 3])

  // When
  const smartBuffer = new BufferReader(buffer)

  // Then
  expect(() => {
    smartBuffer.cursor = 5
  }).toThrow(RangeError)
})