Local webhook testing support

[mrashed-dev]

Description

This PR enables support for local webhook development. When implementing this feature in your app, the SDK will create a tunnel connection to a websocket server and registers it as a webhook callback to your Nylas account.

Usage

During the setup process you can pass in a class that implements WebhookTunnel.WebhookHandler with methods to override the websocket client's callback methods. The most important method is the onMessage method which returns a parsed delta event from the webhook server.

public class NylasWebhook {
  public static void main(String[] args) throws Exception {
    ExampleConf conf = new ExampleConf();
    NylasClient client = new NylasClient();
    NylasApplication application = client.application("CLIENT_ID", "CLIENT_SECRET");

    WebhookTunnel webhookTunnel = new WebhookTunnel.Builder(application, new HandleNotifications()).build();
    webhookTunnel.connect();
  }
}

class HandleNotifications implements WebhookTunnel.WebhookHandler {
  private static final Logger log = LogManager.getLogger(HandleNotifications.class);

  @Override
  public void onOpen(short httpStatusCode) {
    log.info("OnOpen");
  }

  @Override
  public void onClose(int code, String reason, boolean remote) {
    log.info("onClose");
  }

  @Override
  public void onMessage(Notification notification) {
    log.info("onMessage");
  }

  @Override
  public void onError(Exception ex) {
    log.info("onError");
  }
}

License

I confirm that this contribution is made under the terms of the MIT license and that I have the authority necessary to make this contribution on behalf of its copyright owner.