some gif thing.js

function createGifPostToSlack(fs, request, createImageSizeStream, easyimg, GIFEncoder, pngFileStream, browserString, browserName) {
  var imageWidth;
  var imageHeight;
  var screenshotsPath = 'tests/screenshots/'+browserName+'/';
  var resultPath = screenshotsPath+'result.gif';
  var resultPathCompressed = screenshotsPath+'result_compressed.gif';
  var stream;

  var makeGif = function() {
    var encodeGif = function(width, height) {
      var encoder = new GIFEncoder(width, height);
      pngFileStream(screenshotsPath+'?.png')
        .on('end', function() {
          easyimg.resize({src: resultPath, dst: resultPathCompressed, width: imageWidth/2, quality:10}).then(function(file) {
            uploadFileToSlack(file);
          });
        })
        .pipe(encoder.createWriteStream({ repeat: 0, delay: 500, quality: 10 }))
        .pipe(fs.createWriteStream(resultPath));
    };

    encodeGif(imageWidth, imageHeight);
  };

  var uploadFileToSlack = function(file) {
    var r = request.post('https://slack.com/api/files.upload', function optionalCallback (err, httpResponse, body) {
      if (err) {
        return console.error('upload failed:', err);
      }

      if (process.env.TRAVIS_JOB_ID) {
        sendSlackMessage('#' + process.env.TRAVIS_JOB_ID + ' in ' + browserString + ': ' + JSON.parse(body).file.url);
      } else {
        sendSlackMessage((browserString) + ' ' + JSON.parse(body).file.url);
      }
    });

    var form = r.form();
    form.append('token', 'xoxp-2188701673-2236842709-2545311152-1e043e');
    form.append('channels', '#dev_stack');
    form.append('file', fs.createReadStream(resultPathCompressed));
  };

  var sendSlackMessage = function(message) {
   var webhook = (!process.env.TRAVIS_BRANCH || process.env.TRAVIS_BRANCH === 'test') ? 'https://bugherd.slack.com/services/hooks/incoming-webhook?token=wOrZWGjX2QONVT4vCdEBpDZh' : 'https://bugherd.slack.com/services/hooks/incoming-webhook?token=UeWCTRKhpJXRJv8IvI6rnAsw';
   var payload = {
     channel: (!process.env.TRAVIS_BRANCH || process.env.TRAVIS_BRANCH === 'test') ? 'testing' : '#dev_stack',
     username: 'Travis',
     text: message,
     icon_url: 'http://i.imgur.com/2GOrjFe.png',
     markdown: true
   };

   request.post({
     url: webhook,
     body: JSON.stringify(payload)
   }, function(e,r,body) {
      deleteFolderRecursive(screenshotsPath);
      if (body !== 'ok') {
        console.log('Could not post message to Slack');
      }
   });
  };

  var imageSizeStream = createImageSizeStream().on('size', function(dimensions) {
    imageWidth = dimensions.width;
    imageHeight = dimensions.height;

    console.log('width: ' + imageWidth)
    console.log('height: ' + imageHeight)

    makeGif();
    stream.destroy();
  });

  var startProcess = function() {
    fs.exists(screenshotsPath+'0.png', function(exists) {
      if (exists) {
        stream = fs.createReadStream(screenshotsPath+'0.png').pipe(imageSizeStream);
      } else {
        console.log('No screenshots were taken');
      }
    });
  };

  startProcess();

  function serialize(obj) {
    var str = "";
    for (var key in obj) {
      if (str !== "") {
        str += "&";
      }
      str += key + "=" + obj[key];
    }
    return str;
  }

  var deleteFolderRecursive = function(path) {
    if( fs.existsSync(path) ) {
      fs.readdirSync(path).forEach(function(file,index){
        var curPath = path + "/" + file;
        if(fs.lstatSync(curPath).isDirectory()) { // recurse
          deleteFolderRecursive(curPath);
        } else { // delete file
          fs.unlinkSync(curPath);
        }
      });
      fs.rmdirSync(path);
    }
  };
}