test.js

import t from 'tape'
import AudioBufferList from './index.js'
import util from 'audio-buffer-utils'


function getChannelData(list, channel, from, to) {
  if (from == null) from = 0
  if (to == null) to = list.length
  let arr = new Float32Array(to - from)
  list.copyFromChannel(arr, channel, from, to)
  return Array.from(arr)
}

t('create with options argument', t => {
  var a = new AudioBufferList({channels: 3})

  t.equal(a.length, 0)
  t.equal(a.channels, 3)

  t.end()
})

t('create with sample rate', t => {
  var a = new AudioBufferList(0, {sampleRate: 70000})
  a.append(70000)

  t.equal(a.duration, 1)
  t.equal(a.numberOfChannels, 1)

  t.end()
})

//new methods
t('repeat', t => {
  var a = new AudioBufferList(util.create(10, 2))
  a.repeat(0)
  t.equal(a.length, 0)

  var b = new AudioBufferList(util.create(10, 2))
  b.repeat(1)
  t.equal(b.length, 10)

  var c = new AudioBufferList(util.create(10, 2))
  c.repeat(2)
  t.equal(c.length, 20)

  let d = new AudioBufferList(2, 2).repeat(4)
  t.equal(d.numberOfChannels, 2)
  t.equal(d.length, 8)

	t.end()
})

t('full map', t => {
  let list = new AudioBufferList([util.fill(util.create(2, 2), 1), util.fill(util.create(2, 2), 0)])

  let dest = list.map((b, idx) => {
    return util.fill(b, idx)
  })

  t.deepEqual(getChannelData(dest, 0), Array(2).fill(0).concat(Array(2).fill(1)))
  t.deepEqual(getChannelData(dest, 1), Array(2).fill(0).concat(Array(2).fill(1)))

  t.end()
})

t('each last elem', t => {
  let list = new AudioBufferList([0, 1, 2, 3, 4])

  let c = 0
  list.map(b => {
    c++
  }, 1, 3)

  t.equal(c, 1)

  t.end()
})

t('subset map', t => {
  let list2 = new AudioBufferList([util.fill(util.create(4, 2), 0), util.fill(util.create(4, 2), 0)])

  let dest2 = list2.map((b, idx, offset) => {
    return util.fill(b, 1, Math.max(2 - offset, 0), Math.min(6 - offset, b.length))
  }, 2, 6)

  t.deepEqual(getChannelData(dest2, 1), Array(2).fill(0).concat(Array(4).fill(1)).concat(Array(2).fill(0)))

  t.end()
})

t('map subset length', t => {
  //subset length
  let list3 = new AudioBufferList([util.create([0,1,0], 1), util.create([-1,1,0,-1], 1)])
  list3 = list3.map((b, idx) => {return b}, 0, 4)
  t.equal(list3.length, 7)

  t.end()
})

t('map upd channels', t => {
  //upd channels
  let list4 = new AudioBufferList([util.create(1, 1), util.create(1, 2)])
  list4 = list4.map(buf => util.create(1, 3))
  t.equal(list4.numberOfChannels, 3)

  //change itself
  //track offset
  //filter null/zeros
  //recalculates length & duration
  let list5 = new AudioBufferList([util.create([1,1]), util.create([.5,.5]), util.create([-1,-1])])

  list5.map((buf, idx, offset) => {
    if (idx === 0) t.equal(offset, 0)
    else if (idx === 2) {
      t.equal(offset, 4)
      return null
    }

    if (idx === 1) {
      buf.copyToChannel(new Float32Array([0,0]), 0)
    }
  })
  t.deepEqual(list5.length, 4)
  t.deepEqual(getChannelData(list5, 0), [1,1,0,0])
  t.end()
})

t('each', t => {
  //full each
  let list = new AudioBufferList([util.fill(util.create(2, 2), 1), util.fill(util.create(2, 2), 0)])

  list.map((b, idx) => {
    return util.fill(b, idx)
  })

  t.deepEqual(getChannelData(list, 0), Array(2).fill(0).concat(Array(2).fill(1)))
  t.deepEqual(getChannelData(list, 1), Array(2).fill(0).concat(Array(2).fill(1)))

  //subset each
  let list2 = new AudioBufferList([util.fill(util.create(4, 2), 0), util.fill(util.create(4, 2), 0)])

  list2.map((b, idx, offset) => {
    return util.fill(b, 1, Math.max(2 - offset, 0), Math.min(6 - offset, b.length))
  }, 2, 6)

  t.deepEqual(getChannelData(list2, 1), Array(2).fill(0).concat(Array(4).fill(1)).concat(Array(2).fill(0)))

  //change itself
  //track offset
  //filter null/zeros
  //recalculates length & duration
  let list5 = new AudioBufferList([util.create([1,1]), util.create([.5,.5]), util.create([-1,-1])])

  list5.map((buf, idx, offset) => {
    if (idx === 0) t.equal(offset, 0)
    else if (idx === 2) t.equal(offset, 4)

    if (idx === 1) {
      buf.copyToChannel(new Float32Array([0,0]), 0)
    }
  })
  t.deepEqual(list5.length, 6)
  t.deepEqual(getChannelData(list5, 0), [1,1,0,0,-1,-1])

  //break vicious cycle
  let list6 = new AudioBufferList(util.create(2)).repeat(4)
  list6.map((buf, idx, offset) => {
    if (idx > 1) return false
      t.ok(idx <= 1)
  })

  t.end()
})

t('reverse each', t => {
  //do reversed walking
  let list7 = new AudioBufferList(2).repeat(4)
  t.equal(list7.length, 8)
  let arr = []
  list7.reverseMap((buf, idx, offset) => {
    arr.push(idx)
  }, {reversed: true})
  t.deepEqual(arr, [3,2,1,0])

  t.end()
})


t.skip('reverse', t => {
  let list = new AudioBufferList(util.create([0,1,2, 3,4,5])).split(3)

  list.reverse(1,5)

  t.deepEqual(getChannelData(list, 0), [0,4,3,2,1,5])

  t.end()
})


//AudioBuffer methods/props
t('AudioBuffer properties', t => {
	let bl = new AudioBufferList(util.create([0,1,2,3], 2))

	t.equal(bl.length, 2)
	t.equal(bl.numberOfChannels, 2)
	t.equal(bl.duration, 2/bl.sampleRate)

	bl.append(util.create([4,5,6,7,8,9,10,11,12,13], 3))

	t.equal(bl.length, 5)
	t.equal(bl.numberOfChannels, 3)
	t.ok(Math.abs(bl.duration - 5/bl.sampleRate) < 1e-8)

	t.end()
})


t('getChannelData', function (t) {
  let bl = new AudioBufferList([util.create(2, 2), util.create(2, 2), util.create(2, 2)])

  t.equal(getChannelData(bl, 0).length, 6)
  t.equal(getChannelData(bl, 0, 3).length, 3)
  t.equal(getChannelData(bl, 0, 2, 4).length, 2)

  t.end()
})

t('copyToChannel', function (t) {
	var a = new AudioBufferList(util.create(2, 2)).repeat(2);
	var arr = new Float32Array(4);
	arr.fill(-1);

	a.copyToChannel(arr, 0, 0);
	t.deepEqual(arr, getChannelData(a, 0));

	a.copyToChannel(arr, 1, 1);

	var zeros = new Float32Array(1);
	arr.set(zeros);

	t.deepEqual(arr, getChannelData(a, 1));

  a.copyToChannel(new Float32Array([0]), 0, 1)
  t.deepEqual(getChannelData(a, 0), [-1, 0, -1, -1])

	t.end()
})


t('copyFromChannel', function (t) {
	var a = new AudioBufferList(util.fill(util.create(20, 2), (v, idx, channel) => channel ? 1 : -1)).repeat(2);

  var arr
	arr = new Float32Array(40)
	a.copyFromChannel(arr, 0);
	t.deepEqual(arr, getChannelData(a, 0));

	a.copyFromChannel(arr, 1, 10);
	var result = Array(30).fill(1).concat(Array(10).fill(-1));
	t.deepEqual(arr, result);

  arr = new Float32Array(40)
  a.copyFromChannel(arr, 0, 2, 10)
  var result = Array(8).fill(-1).concat(Array(32).fill(0))
  t.deepEqual(arr, result)

  arr = new Float32Array(40)
  a.copyFromChannel(arr, 0, 2, 9)
  var result = Array(7).fill(-1).concat(Array(33).fill(0))
  t.deepEqual(arr, result)

  arr = new Float32Array(40)
  a.copyFromChannel(arr, 0, 2, 11)
  var result = Array(9).fill(-1).concat(Array(31).fill(0))
  t.deepEqual(arr, result)

	t.end()
})

t('split/join', t => {
  let a = new AudioBufferList(10)

  t.equal(a.length, 10)
  t.equal(a.buffers.length, 1)
  t.equal(l(a.buffers), a.length)

  a.split(4)

  t.equal(a.buffers.length, 2)
  t.equal(l(a.buffers), a.length)

  a.split(4)

  t.equal(a.buffers.length, 2)
  t.equal(l(a.buffers), a.length)

  a.split(5)

  t.equal(a.buffers.length, 3)
  t.equal(l(a.buffers), a.length)

  a.split(10)

  t.equal(a.buffers.length, 3)
  t.equal(l(a.buffers), a.length)

  a.split(9,8)

  t.equal(a.buffers.length, 5)
  t.equal(l(a.buffers), a.length)

  a.split([7,6])

  t.equal(a.buffers.length, 7)
  t.equal(l(a.buffers), a.length)

  let x = a.join()

  t.equal(a.buffers.length, 1)
  t.equal(l(a.buffers), a.length)

  function l (bufs) {
    let l = 0
    for (let i = 0; i < bufs.length; i++) {
      l += bufs[i].length
    }
    return l
  }

  t.end()
})

t('join single', t => {
  let l = new AudioBufferList([0, .1, .2, .3])

  l.join(1, 2)

  t.equal(l.buffers.length, 1)
  t.equal(l.buffers[0].length, 4)
  t.equal(l.length, 4)

  t.end()
})

t('remove', t => {
  var a = new AudioBufferList([util.fill(util.create(20, 2), (v, idx, channel) => channel), util.fill(util.create(20, 2), (v, idx, channel) => 1 -channel)]);

  a.remove(10)
  t.equal(a.length, 30)
  t.deepEqual(getChannelData(a,0), Array(10).fill(0).concat(Array(20).fill(1)))
  t.deepEqual(getChannelData(a,1), Array(10).fill(1).concat(Array(20).fill(0)))

  a.remove(8, 10)
  t.equal(a.length, 20)
  t.deepEqual(getChannelData(a,0), Array(8).fill(0).concat(Array(12).fill(1)))
  t.deepEqual(getChannelData(a,1), Array(8).fill(1).concat(Array(12).fill(0)))

  a.remove(-12)
  t.equal(a.length, 8)
  t.deepEqual(getChannelData(a,0), Array(8).fill(0))
  t.deepEqual(getChannelData(a,1), Array(8).fill(1))

  var b = new AudioBufferList([util.create([0,1,2]), util.create([3,4,5])])

  b.remove(1, 4)
  t.equal(b.length, 2)

  var c = new AudioBufferList(3).repeat(2)
  c.remove(5, 3)
  t.equal(c.length, 5)

	t.end()
})

t('insert', t => {
	var a = new AudioBufferList()

	t.equal(a.length, 0)

	a.insert(2, util.fill(util.create(10,2), 2))

	t.equal(a.length, 10)
	t.equal(a.numberOfChannels, 2)
	t.deepEqual(getChannelData(a, 0), Array(10).fill(2))

	a.insert(2, util.fill(util.create(10,2), (v,i,c) => c))

	t.equal(a.length, 20)
	t.deepEqual(getChannelData(a, 0), Array(2).fill(2).concat(Array(10).fill(0)).concat(Array(8).fill(2)))

	a.insert(-5, util.fill(util.create(10, 2), (v,i,c) => 1-c))

	t.equal(a.length, 30)
	t.deepEqual(getChannelData(a, 1), Array(2).fill(2).concat(Array(10).fill(1)).concat(Array(3).fill(2)).concat(Array(10).fill(0)).concat(Array(5).fill(2)))

	t.end()
})

t('insert to the end case', t => {
  let a = new AudioBufferList(7, {numberOfChannels: 3})

  a.insert(0, util.create([[0,.5,1], [0, -.5, -1], [0,0,0]]))
  t.deepEqual(getChannelData(a, 0), [0,.5,1, 0,0,0,0,0,0,0])
  t.deepEqual(getChannelData(a, 1), [0,-.5,-1, 0,0,0,0,0,0,0])
  t.deepEqual(getChannelData(a, 2), [0,0,0, 0,0,0,0,0,0,0])

  a.insert(1, util.create(2, 3))
  t.deepEqual(getChannelData(a, 0), [0,0,0,.5,1, 0,0,0,0,0,0,0])
  t.deepEqual(getChannelData(a, 1), [0,0,0,-.5,-1, 0,0,0,0,0,0,0])
  t.deepEqual(getChannelData(a, 2), [0,0,0,0,0, 0,0,0,0,0,0,0])

  a.insert(-0, util.create([[0,0,0], [0,0,0], [1,1,1]]))
  t.deepEqual(getChannelData(a, 0), [0,0,0,.5,1, 0,0,0,0,0,0,0,0,0,0])
  t.deepEqual(getChannelData(a, 1), [0,0,0,-.5,-1, 0,0,0,0,0,0,0,0,0,0])
  t.deepEqual(getChannelData(a, 2), [0,0,0,0,0, 0,0,0,0,0,0,0,1,1,1])

  t.end()
})


//bl patch methods
t.skip('single bytes from single buffer', function (t) {
  var bl = new AudioBufferList()
  bl.append(util.create([0,1,2,3]))

  t.equal(bl.length, 4)

  t.equal(bl.get(0)[0], 0)
  t.equal(bl.get(1)[0], 1)
  t.equal(bl.get(2)[0], 2)
  t.equal(bl.get(3)[0], 3)

  t.end()
})

t.skip('single bytes from multiple buffers', function (t) {
  var bl = new AudioBufferList()
  bl.append(util.create([1,2,3,4]))
  bl.append(util.create([5,6,7]))
  bl.append(util.create([8,9]))
  bl.append(util.create([10]))

  t.equal(bl.length, 10)

  t.equal(bl.get(0), 1)
  t.equal(bl.get(1), 2)
  t.equal(bl.get(2), 3)
  t.equal(bl.get(3), 4)
  t.equal(bl.get(4), 5)
  t.equal(bl.get(5), 6)
  t.equal(bl.get(6), 7)
  t.equal(bl.get(7), 8)
  t.equal(bl.get(8), 9)
  t.equal(bl.get(9), 10)
  t.end()
})

t('multi bytes from single buffer', function (t) {
  var bl = new AudioBufferList()
  bl.append(util.create([-1, -.5, 0, 1]))

  t.equal(bl.length, 4)

  t.deepEqual(getChannelData(bl.slice(0, 4), 0), [-1, -.5, 0, 1])
  t.deepEqual(getChannelData(bl.slice(0, 3), 0), [-1, -.5, 0])
  t.deepEqual(getChannelData(bl.slice(1, 4), 0), [-.5, 0, 1])
  t.deepEqual(getChannelData(bl.slice(-4, -1), 0), [-1, -.5, 0])

  t.end()
})

t('multi bytes from single buffer (negative indexes)', function (t) {
  var bl = new AudioBufferList()
  bl.append(util.create([1,2,3,4,5,6,7,8,9,10,11,12], 2))

  t.equal(bl.length, 6)

  t.deepEqual(getChannelData(bl.slice(-6, -1), 0), [1,2,3,4,5])
  t.deepEqual(getChannelData(bl.slice(-6, -2), 0), [1,2,3,4])
  t.deepEqual(getChannelData(bl.slice(-5, -2), 0), [2,3,4])

  t.end()
})

t('multiple bytes from multiple buffers', function (t) {
  var bl = new AudioBufferList()

  bl.append(util.create([0,1,2,3]))
  bl.append(util.create([4,5,6]))
  bl.append(util.create([7,8]))
  bl.append(util.create([9]))

  t.equal(bl.length, 10)

  t.deepEqual(getChannelData(bl.slice(0, 10), 0), [0,1,2,3,4,5,6,7,8,9])
  t.deepEqual(getChannelData(bl.slice(3, 10), 0), [3,4,5,6,7,8,9])
  t.deepEqual(getChannelData(bl.slice(3, 6), 0), [3,4,5])
  t.deepEqual(getChannelData(bl.slice(3, 8), 0), [3,4,5,6,7])
  t.deepEqual(getChannelData(bl.slice(5, 10), 0), [5,6,7,8,9])
  t.deepEqual(getChannelData(bl.slice(-7, -4), 0), [3,4,5])

  t.end()
})

t('multiple bytes from multiple buffer lists', function (t) {
  var bl = new AudioBufferList()

  bl.append(new AudioBufferList([ util.create([0,1,2,3]), util.create([4,5,6]) ]))
  bl.append(new AudioBufferList([ util.create([7,8]), util.create([9]) ]))

  t.equal(bl.length, 10)

  t.deepEqual(getChannelData(bl.slice(0, 10), 0), [0,1,2,3,4,5,6,7,8,9])
  t.deepEqual(getChannelData(bl.slice(3, 10), 0), [3,4,5,6,7,8,9])
  t.deepEqual(getChannelData(bl.slice(3, 6), 0), [3,4,5])
  t.deepEqual(getChannelData(bl.slice(3, 8), 0), [3,4,5,6,7])
  t.deepEqual(getChannelData(bl.slice(5, 10), 0), [5,6,7,8,9])

  t.end()
})

// same data as previous test, just using nested constructors
t('multiple bytes from crazy nested buffer lists', function (t) {
  var bl = new AudioBufferList()

  bl.append(new AudioBufferList([
      new AudioBufferList([
          new AudioBufferList(util.create([0,1,2]))
        , util.create([3])
        , new AudioBufferList(util.create([4,5,6]))
      ])
    , new AudioBufferList([ util.create([7,8]) ])
    , new AudioBufferList(util.create([9]))
  ]))

  t.equal(bl.length, 10)

  t.deepEqual(getChannelData(bl.slice(0, 10), 0), [0,1,2,3,4,5,6,7,8,9])

  t.deepEqual(getChannelData(bl.slice(3, 10), 0), [3,4,5,6,7,8,9])
  t.deepEqual(getChannelData(bl.slice(3, 6), 0), [3,4,5])
  t.deepEqual(getChannelData(bl.slice(3, 8), 0), [3,4,5,6,7])
  t.deepEqual(getChannelData(bl.slice(5, 10), 0), [5,6,7,8,9])

  t.end()
})

t('append accepts arrays of Buffers', function (t) {
  var bl = new AudioBufferList()
  bl.append(util.create([0,1,2]))
  bl.append([ util.create([3,4,5]) ])
  bl.append([ util.create([6,7,8]), util.create([9,10,11]) ])
  bl.append([ util.create([12,13,14,15]), util.create([16,17,18,19,20]), util.create([21,22,23,24,25]) ])

  t.equal(bl.length, 26)

  t.deepEqual(getChannelData(bl, 0), [0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25])
  t.end()
})

t('append accepts arrays of AudioBufferLists', function (t) {
  var bl = new AudioBufferList()
  bl.append(util.create([0,1,2]))
  bl.append([ new AudioBufferList(util.create([3,4,5])) ])
  bl.append(new AudioBufferList([ util.create([6,7,8]), new AudioBufferList(util.create([9,10,11])) ]))
  bl.append([ util.create([12,13,14,15]), new AudioBufferList([ util.create([16,17,18,19,20]), util.create([21,22,23,24,25]) ]) ])
  t.equal(bl.length, 26)
  t.deepEqual(getChannelData(bl, 0), [0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25])
  t.end()
})

t('append chainable', function (t) {
  var bl = new AudioBufferList()
  t.ok(bl.append(util.create([0,1,2,3])) === bl)
  t.ok(bl.append([ util.create([0,1,2,3]) ]) === bl)
  t.ok(bl.append(new AudioBufferList(util.create([0,1,2,3]))) === bl)
  t.ok(bl.append([ new AudioBufferList(util.create([0,1,2,3])) ]) === bl)
  t.end()
})

t('append chainable (test results)', function (t) {
  var bl = new AudioBufferList(util.create([0,1,2]))
    .append([ new AudioBufferList(util.create([3,4,5])) ])
    .append(new AudioBufferList([ util.create([6,7,8]), new AudioBufferList(util.create([9,10,11])) ]))
    .append([ util.create([12,13,14,15]), new AudioBufferList([ util.create([16,17,18,19,20]), util.create([21,22,23,24,25]) ]) ])

  t.equal(bl.length, 26)
  t.deepEqual(getChannelData(bl, 0), [0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25])
  t.end()
})

t('consuming from multiple buffers', function (t) {
  var bl = new AudioBufferList()

  bl.append(util.create([0,1,2,3]))
  bl.append(util.create([4,5,6]))
  bl.append(util.create([7,8]))
  bl.append(util.create([9]))

  t.equal(bl.length, 10)

  t.deepEqual(getChannelData(bl.slice(0, 10), 0), [0,1,2,3,4,5,6,7,8,9])

  bl.remove(3)
  t.equal(bl.length, 7)
  t.deepEqual(getChannelData(bl.slice(0, 7), 0), [3,4,5,6,7,8,9])

  bl.remove(2)
  t.equal(bl.length, 5)
  t.deepEqual(getChannelData(bl.slice(0, 5), 0), [5,6,7,8,9])

  bl.remove(1)
  t.equal(bl.length, 4)
  t.deepEqual(getChannelData(bl.slice(0, 4), 0), [6,7,8,9])

  bl.remove(1)
  t.equal(bl.length, 3)
  t.deepEqual(getChannelData(bl.slice(0, 3), 0), [7,8,9])

  bl.remove(2)
  t.equal(bl.length, 1)
  t.deepEqual(getChannelData(bl.slice(0, 1), 0), [9])

  t.end()
})

t('complete consumption', function (t) {
  var bl = new AudioBufferList()

  bl.append(util.create([0]))
  bl.append(util.create([1]))

  bl.remove(2)

  t.equal(bl.length, 0)
  t.equal(bl.buffers.length, 0)

  t.end()
})

t('test readUInt16LE / readUInt16BE / readInt16LE / readInt16BE', function (t) {
  var buf1 = util.create(1)
    , buf2 = util.create(3)
    , buf3 = util.create(3)
    , bl   = new AudioBufferList()

  buf2[1] = 0x3
  buf2[2] = 0x4
  buf3[0] = 0x23
  buf3[1] = 0x42

  bl.append(buf1)
  bl.append(buf2)
  bl.append(buf3)

  t.throws(function () {
	  bl.readUInt16BE(2) // 0x0304
	  bl.readUInt16LE(2) // 0x0403
	  bl.readInt16BE(2) // 0x0304
	  bl.readInt16LE(2) // 0x0403
	  bl.readUInt16BE(3) // 0x0423
	  bl.readUInt16LE(3) // 0x2304
	  bl.readInt16BE(3) // 0x0423
	  bl.readInt16LE(3) // 0x2304
	  bl.readUInt16BE(4) // 0x2342
	  bl.readUInt16LE(4) // 0x4223
	  bl.readInt16BE(4) // 0x2342
	  bl.readInt16LE(4) // 0x4223
  })
  t.end()
})


t('basic copy', function (t) {
  var buf  = util.noise(util.create(1024))
    , buf2 = util.create(1024)
    , b    = new AudioBufferList(buf)
  b.copy(buf2)
  t.deepEqual(getChannelData(b, 0), getChannelData(buf2, 0), 'same buffer')
  t.end()
})

t('copy after many appends', function (t) {
  var buf  = util.noise(util.create(512))
    , buf2 = util.create(1024)
    , b    = new AudioBufferList(buf)

  b.append(buf)
  b.copy(buf2)
  t.deepEqual(getChannelData(b, 0), getChannelData(buf2, 0), 'same buffer')
  t.end()
})

t('copy at a precise position', function (t) {
  var buf  = util.noise(util.create(1004))
    , buf2 = util.create(1024)
    , b    = new AudioBufferList(buf)

  b.copy(buf2, 20)
  t.deepEqual(getChannelData(b, 0), util.slice(buf2, 20).getChannelData(0), 'same buffer')
  t.end()
})

t('copy starting from a precise location', function (t) {
  var buf  = util.noise(util.create(10))
    , buf2 = util.create(5)
    , b    = new AudioBufferList(buf)

  b.copy(buf2, 0, 5)
  t.deepEqual(getChannelData(b.slice(0, 5), 0), buf2.getChannelData(0), 'same buffer')
  t.end()
})

t('copy in an interval', function (t) {
  var rnd      = util.noise(util.create(10))
    , b        = new AudioBufferList(rnd) // put the random bytes there
    , actual   = util.create(3)
    , expected = util.create(3)

  util.copy(util.subbuffer(rnd, 5,8), expected, 0)
  b.copy(actual, 0, 5, 8)

  t.deepEqual(actual.getChannelData(0), expected.getChannelData(0), 'same buffer')
  t.end()
})

t('copy an interval between two buffers', function (t) {
  var buf      = util.noise(util.create(10))
    , buf2     = util.create(10)
    , b        = new AudioBufferList(buf)

  b.append(buf)
  b.copy(buf2, 0, 5, 15)

  t.deepEqual(getChannelData(b.slice(5, 15), 0), buf2.getChannelData(0), 'same buffer')
  t.end()
})

t('shallow slice across buffer boundaries', function (t) {
  var bl = new AudioBufferList([util.create([0,0,0,0,0]), util.create([1,1,1,1,1,1]), util.create([2,2,2,2,2])])

  t.deepEqual(getChannelData(bl.slice(3, 13), 0), [0,0,1,1,1,1,1,1,2,2])
  t.end()
})

t('shallow slice within single buffer', function (t) {
  var bl = new AudioBufferList(util.create([0,1,2,3,4,5,6,7,8]))

  t.deepEqual(getChannelData(bl.slice(3, 6), 0), [3,4,5])
  t.end()
})

t('shallow slice single buffer', function (t) {
  t.plan(3)
  var bl = new AudioBufferList([util.create([0,0,0,0,0]), util.create([1,1,1,1,1,1]), util.create([2,2,2,2,2])])

  t.deepEqual(getChannelData(bl.slice(0, 5), 0), util.create([0,0,0,0,0]).getChannelData(0))
  t.deepEqual(getChannelData(bl.slice(5, 11), 0), util.create([1,1,1,1,1,1]).getChannelData(0))
  t.deepEqual(getChannelData(bl.slice(11, 16), 0), util.create([2,2,2,2,2]).getChannelData(0))
})

t('shallow slice with negative or omitted indices', function (t) {
  t.plan(4)
  var bl = new AudioBufferList([util.create([0,0,0,0,0]), util.create([1,1,1,1,1,1]), util.create([2,2,2,2,2])])

  t.deepEqual(getChannelData(bl.slice(), 0), '0000011111122222'.split('').map(v => parseFloat(v)))
  t.deepEqual(getChannelData(bl.slice(5), 0), '11111122222'.split('').map(v => parseFloat(v)))
  t.deepEqual(getChannelData(bl.slice(5, -3), 0), '11111122'.split('').map(v => parseFloat(v)))
  t.deepEqual(getChannelData(bl.slice(-8), 0), '11122222'.split('').map(v => parseFloat(v)))
})

t('shallow slice does not make a copy', function (t) {
  t.plan(1)
  var buffers = [util.create(util.create([0,0,0,0,0])), util.create(util.create([1,1,1,1,1,1])), util.create(util.create([2,2,2,2,2]))]
  var bl = (new AudioBufferList(buffers)).slice(5, -3)

  util.fill(buffers[1],0)
  util.fill(buffers[2],0)

  t.deepEqual(getChannelData(bl, 0), [0,0,0,0,0,0,0,0])
})

t('clone', function (t) {
  t.plan(2)

  var bl = new AudioBufferList(util.create([0,1,2,3,4,5,6,7,8,9]))
    , dup = bl.copy()

  t.equal(bl.prototype, dup.prototype)
  t.deepEqual(getChannelData(bl, 0), getChannelData(dup, 0))
})

t('destroy no pipe', function (t) {
  t.plan(2)

  var bl = new AudioBufferList(util.create([0,1,0,1,0,1,0,1]))
  bl.destroy()

  t.equal(bl.buffers, null)
  t.equal(bl.length, 0)
})

t('slice', function (t) {
  var l = new AudioBufferList(10, 2)

  t.equal(l.numberOfChannels, 2)

  l.remove(10)

  t.equal(l.numberOfChannels, 2)

  let m = l.slice()

  t.equal(m.numberOfChannels, 2)

  t.end()
})

t('zero buffers', function (t) {
  let a = new AudioBufferList(0, 2)
  t.equal(a.buffers.length, 0)

  let b = new AudioBufferList(10, 2)
  let c = b.slice(0,0)
  t.equal(c.length, 0)
  t.equal(c.buffers.length, 0)

  t.end()
})

t('update number of channels', function (t) {
  let a = new AudioBufferList(3, 3)

  t.equal(a.numberOfChannels, 3)

  let b = new AudioBufferList(0, 2)

  t.equal(b.numberOfChannels, 2)
  t.equal(b.length, 0)
  t.equal(b.buffers.length, 0)

  b.append(util.create(1))

  t.equal(b.length, 1)
  t.equal(b.numberOfChannels, 1)

  t.end()
})

t('remove 0-len should return null', function (t) {
  let a = new AudioBufferList(10)
  t.ok(a.remove(10))
  t.notOk(a.remove(10))
  t.end()
})

t('copy(from, to)', function (t) {
  let a = new AudioBufferList([0, 1, 2, 3, 4, 5])

  t.equal(a.length, 6)

  let b = a.copy(1,4)
  t.deepEqual(b.getChannelData(0), [1,2,3])

  t.end()
})