blob-util/test/test.js

'use strict'

/* global describe, it, atob, before */

if (typeof Promise === 'undefined') {
  window.Promise = require('native-or-lie')
}

var blobUtil = require('../dist/blob-util.cjs.js')

var chai = require('chai')
chai.use(require('chai-as-promised'))

var should = chai.should()

var transparent1x1Png =
  'iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR4nGP6zwAAAg' +
  'cBApocMXEAAAAASUVORK5CYII='
var black1x1Png =
  'iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAAAAAA6fptVAAAACklEQVR4nGNiAAAABg' +
  'ADNjd8qAAAAABJRU5ErkJggg=='

describe('basic tests', function () {
  this.timeout(30000)

  before(function () {
    var img = document.createElement('img')
    img.src = 'test/kirby.gif'
    img.id = 'kirby'
    document.body.appendChild(img)

    var transparent = document.createElement('img')
    transparent.src = 'data:image/png;base64,iVBORw0KGgoAAAANSUh' +
      'EUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR4nGP6zwAAAgcBApocMXEA' +
      'AAAASUVORK5CYII='
    transparent.id = 'transparent'
    document.body.appendChild(transparent)
  })

  it('convert plain blobs', function () {
    var blob = blobUtil.createBlob(['foo'], 'text/plain')
    blob.type.should.equal('text/plain')
    return blobUtil.blobToBase64String(blob).then(function (base64) {
      base64.should.equal('Zm9v')
    })
  })

  it('convert regular gif', function () {
    var img = document.getElementById('kirby')
    return blobUtil.imgSrcToBlob(img.src).then(function (blob) {
      blob.type.should.equal('image/png')
      return blobUtil.blobToBase64String(blob).then(function (base64) {
        should.exist(base64)
      })
    })
  })

  it('convert regular gif as jpeg', function () {
    var img = document.getElementById('kirby')
    return blobUtil.imgSrcToBlob(img.src, 'image/jpeg').then(function (blob) {
      blob.type.should.equal('image/jpeg')
      return blobUtil.blobToBase64String(blob).then(function (base64) {
        should.exist(base64)
      })
    })
  })

  it('convert regular gif to canvas and back', function () {
    var img = document.getElementById('kirby')
    return blobUtil.imgSrcToBlob(img.src).then(function (blob) {
      blob.type.should.equal('image/png')

      var url = blobUtil.createObjectURL(blob)
      return blobUtil.imgSrcToBlob(url).then(function (otherBlob) {
        return Promise.all([
          blobUtil.blobToBase64String(blob),
          blobUtil.blobToBase64String(otherBlob)
        ]).then(function (strings) {
          strings[0].should.equal(strings[1])
        })
      })
    })
  })

  it('convert base64 to png', function () {
    return Promise.resolve(blobUtil.base64StringToBlob(transparent1x1Png, 'image/png')).then(function (blob) {
      return blobUtil.blobToBase64String(blob)
    }).then(function (string) {
      string.should.equal(transparent1x1Png)
    })
  })

  it('convert base64 to png 2', function () {
    return Promise.resolve(blobUtil.base64StringToBlob(black1x1Png, 'image/png')).then(function (blob) {
      return blobUtil.blobToBase64String(blob)
    }).then(function (string) {
      string.should.equal(black1x1Png)
    })
  })

  it('convert data url', function () {
    var dataURL = 'data:image/png;base64,' + transparent1x1Png
    return Promise.resolve(blobUtil.dataURLToBlob(dataURL)).then(function (blob) {
      return blobUtil.blobToBase64String(blob)
    }).then(function (string) {
      string.should.equal(transparent1x1Png)
    })
  })

  it('convert blob to data url', function () {
    var blob = blobUtil.createBlob(['foo'], 'text/plain')
    return blobUtil.blobToDataURL(blob).then(function (dataURL) {
      dataURL.should.equal('data:text/plain;base64,Zm9v')
    })
  })

  it('convert img to dataURL', function () {
    var img = document.getElementById('transparent')
    return blobUtil.imgSrcToDataURL(img.src).then(function (url) {
      url.should.match(/^data:image\/png;base64/)
    })
  })

  it('convert img to dataURL 2', function () {
    var img = document.getElementById('kirby')
    return blobUtil.imgSrcToDataURL(img.src).then(function (url) {
      url.should.match(/^data:image\/png;base64/)
    })
  })

  it('convert img to dataURL 3', function () {
    var img = document.getElementById('kirby')
    return blobUtil.imgSrcToDataURL(img.src, 'image/jpeg').then(function (url) {
      url.should.match(/^data:image\/jpeg;base64/)
    })
  })

  it('convert to binary and back', function () {
    var binary = atob(transparent1x1Png)
    return Promise.resolve(blobUtil.binaryStringToBlob(binary, 'image/png')).then(function (blob) {
      blob.size.should.equal(68)
      return blobUtil.blobToBase64String(blob).then(function (base64) {
        base64.should.equal(transparent1x1Png)
        return blobUtil.blobToBinaryString(blob)
      }).then(function (bin) {
        bin.should.equal(atob(transparent1x1Png))
      })
    })
  })

  it('convert to array buffer and back', function () {
    var bin = atob(transparent1x1Png)
    var buffer = new ArrayBuffer(bin.length)
    var arr = new Uint8Array(buffer)
    for (var i = 0; i < bin.length; i++) {
      arr[i] = bin.charCodeAt(i)
    }
    return Promise.resolve(blobUtil.arrayBufferToBlob(buffer, 'image/png')).then(function (blob) {
      blob.size.should.equal(68)
      return blobUtil.blobToBase64String(blob).then(function (base64) {
        base64.should.equal(transparent1x1Png)
        return blobUtil.blobToBinaryString(blob)
      }).then(function (bin) {
        bin.should.equal(atob(transparent1x1Png))
        return blobUtil.blobToArrayBuffer(blob)
      }).then(function (buff) {
        buff.byteLength.should.equal(68)
        return blobUtil.arrayBufferToBlob(buff, 'image/png')
      }).then(function (blob) {
        return blobUtil.blobToBase64String(blob)
      }).then(function (base64) {
        base64.should.equal(transparent1x1Png)
      })
    })
  })

  it('convert with specific quality', function () {
    var img = document.getElementById('kirby')
    return blobUtil.imgSrcToBlob(img.src, 'image/jpeg', undefined, 1).then(function (blob) {
      return blobUtil.imgSrcToBlob(img.src, 'image/jpeg', undefined, 0.5).then(function (lowQualityBlob) {
        lowQualityBlob.size.should.be.lessThan(blob.size)
      })
    })
  })

  it('convert array buffer to binary string and back', function () {
    var bin = atob(transparent1x1Png)
    var buffer = new ArrayBuffer(bin.length)
    var arr = new Uint8Array(buffer)
    for (var i = 0; i < bin.length; i++) {
      arr[i] = bin.charCodeAt(i)
    }

    var outputBin = blobUtil.arrayBufferToBinaryString(buffer)
    var outputBuff = blobUtil.binaryStringToArrayBuffer(bin)

    outputBin.should.equal(bin)
    blobUtil.arrayBufferToBinaryString(outputBuff).should.equal(bin)
  })
})