Mailspring/app/internal_packages/remove-tracking-pixels/lib/main.es6

import {
  ExtensionRegistry,
  MessageViewExtension,
  ComposerExtension,
  RegExpUtils,
} from 'mailspring-exports';

const TrackingBlacklist = [
  {
    name: 'Sidekick',
    pattern: 't.signaux',
    homepage: 'http://getsidekick.com',
  },
  {
    name: 'Sidekick',
    pattern: 't.senal',
    homepage: 'http://getsidekick.com',
  },
  {
    name: 'Sidekick',
    pattern: 't.sidekickopen',
    homepage: 'http://getsidekick.com',
  },
  {
    name: 'Sidekick',
    pattern: 't.sigopn',
    homepage: 'http://getsidekick.com',
  },
  {
    name: 'Banana Tag',
    pattern: 'bl-1.com',
    homepage: 'http://bananatag.com',
  },
  {
    name: 'Boomerang',
    pattern: 'mailstat.us/tr',
    homepage: 'http://boomeranggmail.com',
  },
  {
    name: 'Cirrus Inisght',
    pattern: 'tracking.cirrusinsight.com',
    homepage: 'http://cirrusinsight.com',
  },
  {
    name: 'Yesware',
    pattern: 'app.yesware.com',
    homepage: 'http://yesware.com',
  },
  {
    name: 'Yesware',
    pattern: 't.yesware.com',
    homepage: 'http://yesware.com',
  },
  {
    name: 'Streak',
    pattern: 'mailfoogae.appspot.com',
    homepage: 'http://streak.com',
  },
  {
    name: 'LaunchBit',
    pattern: 'launchbit.com/taz-pixel',
    homepage: 'http://launchbit.com',
  },
  {
    name: 'MailChimp',
    pattern: 'list-manage.com/track',
    homepage: 'http://mailchimp.com',
  },
  {
    name: 'Postmark',
    pattern: 'cmail1.com/t',
    homepage: 'http://postmarkapp.com',
  },
  {
    name: 'iContact',
    pattern: 'click.icptrack.com/icp/',
    homepage: 'http://icontact.com',
  },
  {
    name: 'Infusionsoft',
    pattern: 'infusionsoft.com/app/emailOpened',
    homepage: 'http://infusionsoft.com',
  },
  {
    name: 'Intercom',
    pattern: 'via.intercom.io/o',
    homepage: 'http://intercom.io',
  },
  {
    name: 'Mandrill',
    pattern: 'mandrillapp.com/track',
    homepage: 'http://mandrillapp.com',
  },
  {
    name: 'Hubspot',
    pattern: 't.hsms06.com',
    homepage: 'http://hubspot.com',
  },
  {
    name: 'RelateIQ',
    pattern: 'app.relateiq.com/t.png',
    homepage: 'http://relateiq.com',
  },
  {
    name: 'RJ Metrics',
    pattern: 'go.rjmetrics.com',
    homepage: 'http://rjmetrics.com',
  },
  {
    name: 'Mixpanel',
    pattern: 'api.mixpanel.com/track',
    homepage: 'http://mixpanel.com',
  },
  {
    name: 'Front App',
    pattern: 'web.frontapp.com/api',
    homepage: 'http://frontapp.com',
  },
  {
    name: 'Mailtrack.io',
    pattern: 'mailtrack.io/trace',
    homepage: 'http://mailtrack.io',
  },
  {
    name: 'Salesloft',
    pattern: 'sdr.salesloft.com/email_trackers',
    homepage: 'http://salesloft.com',
  },
];

export function rejectImagesInBody(body, callback) {
  const spliceRegions = [];
  const regex = RegExpUtils.imageTagRegex();

  // Identify img tags that should be cut
  let result = null;
  while ((result = regex.exec(body)) !== null) {
    if (callback(result[1])) {
      spliceRegions.push({ start: result.index, end: result.index + result[0].length });
    }
  }
  // Remove them all, from the end of the string to the start
  let updated = body;
  spliceRegions.reverse().forEach(({ start, end }) => {
    updated = updated.substr(0, start) + updated.substr(end);
  });

  return updated;
}

export function removeTrackingPixels(message) {
  const isFromMe = message.isFromMe();

  message.body = rejectImagesInBody(message.body, imageURL => {
    if (isFromMe) {
      // If the image is sent by the user, remove all forms of tracking pixels.
      // They could be viewing an email they sent with Salesloft, etc.
      for (const item of TrackingBlacklist) {
        if (imageURL.indexOf(item.pattern) >= 0) {
          return true;
        }
      }
    }

    // Remove Nylas read receipt pixels for the current account. If this is a
    // reply, our read receipt could still be in the body and could trigger
    // additional opens. (isFromMe is not sufficient!)
    if (imageURL.indexOf(`getmailspring.com/open/${message.accountId}`) >= 0) {
      return true;
    }
    return false;
  });
}

class TrackingPixelsMessageExtension extends MessageViewExtension {
  static formatMessageBody = ({ message }) => {
    removeTrackingPixels(message);
  };
}

class TrackingPixelsComposerExtension extends ComposerExtension {
  static prepareNewDraft = ({ draft }) => {
    removeTrackingPixels(draft);
  };
}

export function activate() {
  ExtensionRegistry.MessageView.register(TrackingPixelsMessageExtension);
  ExtensionRegistry.Composer.register(TrackingPixelsComposerExtension);
}

export function deactivate() {
  ExtensionRegistry.MessageView.unregister(TrackingPixelsMessageExtension);
  ExtensionRegistry.Composer.unregister(TrackingPixelsComposerExtension);
}