nightmare-download-manager/nightmare-download-manager.js

Add download management to NightmareJS

var sliced = require('sliced'),
  debug = require('debug')('nightmare:download-manager');

module.exports = exports = function (Nightmare) {
  Nightmare.action('downloadManager',
    function (ns, options, parent, win, renderer, done) {
      var fs = require('fs-extra')
      join = require('path')
        .join,
        sliced = require('sliced');

      var app = require('electron').app;

      win.webContents.session.on('will-download',
        function (event, downloadItem, webContents) {
          parent.emit('log', 'will-download');
          if (options.ignoreDownloads) {
            downloadItem.cancel();
            return;
          }
          downloadItem.pause();

          var downloadInfo = {
            filename: downloadItem.getFilename(),
            mimetype: downloadItem.getMimeType(),
            receivedBytes: 0,
            totalBytes: downloadItem.getTotalBytes(),
            url: downloadItem.getURL(),
            path: join(app.getPath('downloads'), downloadItem.getFilename())
          };

          downloadItem.on('done', function (e, state) {
            if (state == 'completed') {
              fs.move(join(app.getPath('downloads'), downloadItem.getFilename()), downloadInfo.path, function (err) {
                parent.emit('download', state, downloadInfo);
              })
            } else {
              parent.emit('download', state, downloadInfo);
            }
          });

          downloadItem.on('updated', function (event) {
            downloadInfo.receivedBytes = event.sender.getReceivedBytes();
            parent.emit('download', 'updated', downloadInfo);
          });

          downloadItem.setSavePath(downloadInfo.path);

          var handler = function () {
            var arguments = sliced(arguments)
              .filter(function (arg) {
                return !!arg;
              });
            var item, path;
            if (arguments.length == 1 && arguments[0] === Object(arguments[0])) {
              item = arguments[0];
            } else if (arguments.length == 2) {
              path = arguments[0];
              item = arguments[1];
            }

            parent.removeListener('download', handler);
            if (item.filename == downloadItem.getFilename()) {
              if (path == 'cancel') {
                downloadItem.cancel();
              } else {
                if (path && path !== 'continue') {
                  //.setSavePath() does not overwrite the first .setSavePath() call
                  //use `fs.move` when download is completed
                  downloadInfo.path = path;
                }

                if (item && downloadInfo.receivedBytes / item.totalBytes == 1) {
                  parent.emit('log', 'download appears to already be complete, skipping');
                  fs.move(join(app.getPath('downloads'), downloadInfo.filename), downloadInfo.path, () =>{
                    parent.emit('log', 'marking download as (pre) complete');
                    parent.emit('download', 'completed', downloadInfo);
                  });
                } else {
                  downloadItem.resume();
                }
              }
            }
          };

          parent.on('download', handler);
          parent.emit('log', 'will-download about bubble to parent');
          parent.emit('download', 'started', downloadInfo);
        });
      done();
    },
    function (done) {
      debug('downloadManager', 'setting up downloads hash');
      var self = this;
      self._downloads = self._downloads || {};
      self.child.on('download', function (state, downloadInfo) {
        debug('download', downloadInfo.filename + ' is ' + state + ': ' + ((downloadInfo.receivedBytes / downloadInfo.totalBytes) * 100)
          .toFixed(2) + '%');
        self._downloads[downloadInfo.filename] = downloadInfo;
        if(self._downloads[downloadInfo.filename].state != 'completed'){
          self._downloads[downloadInfo.filename].state = state;
        }else{
          debug('download', `${downloadInfo.filename} is already completed, not updating to ${state}`);
        }
        if (self.child.listeners('download')
          .length == 1 && state == 'started') {
          if (self.options.ignoreDownloads) {
            self.child.emit('download', 'cancel', downloadInfo);
          } else {
            self.child.emit('download', 'continue', downloadInfo);
          }
        }
      });
      done();
      return this;
    });

  Nightmare.action('waitDownloadsComplete', function (done) {
    debug('waitDownloadsComplete', 'waiting for downloads to finish');

    var self = this;
    var dldone = function () {
      return Object.keys(self._downloads)
        .map(key => self._downloads[key])
        .filter(function (item) {
          return item.state != 'completed' && item.state != 'interrupted' && item.state != 'cancelled';
        }) == 0;
    };

    var _waitMsPassed = 0,
      _timeoutMs = 250,
      _elapsed = 0;


    var waitDownloads = function waitDownloads(self, done) {
      if (dldone()) {
        return done();
      } else if (self.options.downloadTimeout && (_waitMsPassed > self.options.downloadTimeout)) {
        _waitMsPassed = 0;
        return done(new Error('.wait() for download timed out after ' + self.options.downloadTimeout + 'msec'));
      } else {
        _waitMsPassed += _timeoutMs;
        setTimeout(function () {
          waitDownloads(self, done);
        }, _timeoutMs);
      }
    };

    var waitResponse = function () {
      setTimeout(function () {
        if (Object.keys(self._downloads || {})
          .length > 0) {
          waitDownloads(self, done);
        } else if (_elapsed < (self.options.downloadResponseWait || 3000)) {
          _elapsed += 100;
          waitResponse();
        } else if (_elapsed >= (self.options.downloadResponseWait || 3000)) {
          return done(new Error('.wait() for download never received a download after ' + (self.options.downloadResponseWait || 3000)));
        }
      }, 100);
    };

    if (!self.options.ignoreDownloads) {
      waitResponse();
    } else {
      done();
    }
  });

  Nightmare.prototype.emit = function () {
    this.child.emit.apply(this, sliced(arguments));
    return this;
  };
};