dist/flow.js
function (chunk, event, message) {
      switch (event) {
        case 'progress':
          if (Date.now() - this._lastProgressCallback <
            this.flowObj.opts.progressCallbacksInterval) {
            break;
          }
          this.measureSpeed();
          this.flowObj.fire('fileProgress', this, chunk);
          this.flowObj.fire('progress');
          this._lastProgressCallback = Date.now();
          break;
        case 'error':
          this.error = true;
          this.abort(true);
          this.flowObj.fire('fileError', this, message, chunk);
          this.flowObj.fire('error', message, this, chunk);
          break;
        case 'success':
          if (this.error) {
            return;
          }
          this.measureSpeed();
          this.flowObj.fire('fileProgress', this, chunk);
          this.flowObj.fire('progress');
          this._lastProgressCallback = Date.now();
          if (this.isComplete()) {
            this.currentSpeed = 0;
            this.averageSpeed = 0;
            this.flowObj.fire('fileSuccess', this, message, chunk);
          }
          break;
        case 'retry':
          this.flowObj.fire('fileRetry', this, chunk);
          break;
      }
    }
function (chunk, event, message) {
      switch (event) {
        case 'progress':
          if (Date.now() - this._lastProgressCallback <
            this.flowObj.opts.progressCallbacksInterval) {
            break;
          }
          this.measureSpeed();
          this.flowObj.fire('fileProgress', this, chunk);
          this.flowObj.fire('progress');
          this._lastProgressCallback = Date.now();
          break;
        case 'error':
          this.error = true;
          this.abort(true);
          this.flowObj.fire('fileError', this, message, chunk);
          this.flowObj.fire('error', message, this, chunk);
          break;
        case 'success':
          if (this.error) {
            return;
          }
          this.measureSpeed();
          this.flowObj.fire('fileProgress', this, chunk);
          this.flowObj.fire('progress');
          this._lastProgressCallback = Date.now();
          if (this.isComplete()) {
            this.currentSpeed = 0;
            this.averageSpeed = 0;
            this.flowObj.fire('fileSuccess', this, message, chunk);
          }
          break;
        case 'retry':
          this.flowObj.fire('fileRetry', this, chunk);
          break;
      }
    }
For internal usage only.
Callback when something happens within the chunk.
@function
@param {FlowChunk} chunk
@param {string} event can be 'progress', 'success', 'error' or 'retry'
@param {string} [message]