Test and debug a Node.js app with Bluemix Live Sync

Last updated: 23 June 2016

Testing and debugging are critical to ensure that your app runs without unexpected results. In IBM® Bluemix® DevOps Services, you can test and debug Node.js apps right from the Web IDE. Bluemix Live Sync provides tools to deploy and edit your code within a test environment. You can view simple code updates immediately in the running app without the need to redeploy. Bluemix Live Sync works both from the Web IDE or the command line, so you can choose where to develop your app and have all of the benefits of deploying with Bluemix.

In this tutorial, you create a launch configuration that you use to deploy a Node.js app to a test environment. You enable Live Edit mode in the Web IDE, and then debug your app. If you prefer to work from the command line, you can set up the Bluemix Live Sync command-line tool.

Before you begin

  • To do this tutorial, you need a Bluemix account. Bluemix accounts provide access to everything you need to develop, track, plan, and deploy apps. You can sign up for a free 30-day trial.

  • If you don't already have a Node.js project to work with, create one.
  • To develop locally from your desktop, download and install the Bluemix Live Sync command-line interface for Windows or for Mac OS X.

    Important: The Live Sync command-line interface is available only for Windows 7 and 8 and Mac OS X version 10.9 or later. Learn more about the Live Sync command-line interface.

The run bar

The run bar, which is located within the Web IDE, provides all of the controls for Bluemix Live Sync. On the bar, you can see the deployed state of your app. You can also deploy, stop, and open the app, open its Dashboard, and view logs. If you're developing a Node.js app, the run bar contains icons to enable Live Edit mode, quickly restart the app, and open debugging tools.

Run bar

You can use the run bar to quickly test and debug code in a personal environment before you push the code into production. When you use the run bar to deploy your code, only the code that is in your workspace is deployed. You have complete control to test and experiment before you check in any of your code.

Create a launch configuration

Launch configurations define the settings that the Web IDE uses to deploy your app on Bluemix. By default, DevOps Services deploys to the bound Bluemix app that is associated with the DevOps Services project. If you want to deploy your app locally, you first must create a launch configuration.

  1. On the run bar, click the Launch configuration list and then click the Create a new launch configuration icon. Clicking Plus icon in the run bar
  2. In the Edit Launch Configuration window, add text to the app's name and host to indicate that the app is a test version of your app. In the following example, –live is added to the name and host. DevOps Services provides an initial launch configuration name automatically, but you can change the name if needed. Edit Launch Configuration menu
  3. Click Next to edit the manifest settings for the launch configuration. The manifest file defines how your project is deployed. The file includes information such as memory and instance allotments and is also where you can specify any services to bind to the app. You can create several launch configurations to test different app setups. For information about creating a manifest, see the Bluemix documentation about application manifests.
    Edit Launch Configuration menu
  4. Click SAVE.

You can now use your launch configuration to deploy the contents of your workspace to the test environment that you specified in the configuration.

Deploy an app to a test environment

  1. To deploy your app, click the deploy icon The deploy icon on the run bar. When you click the icon, an instance of your app is deployed by using the current contents of your workspace and the environment that is defined in your launch configuration.
  2. After your app is deployed, you can also complete any of these actions: Run bar

    • The stop icon Stop the app.
    • The open app URL icon Open the deployed app.
    • The view logs icon View the logs of the deployed app.
    • The open dashboard icon Open the app's Dashboard.
    • The enable live edit slider If you are developing a Node.js app, enable Live Edit mode.

Turn on Live Edit mode

Redeploying an app can waste valuable time when you are testing minor changes. To save time, turn on Live Edit mode. When Live Edit mode is on, you can quickly edit a Node.js app and preview the changes immediately.

  1. On the run bar, select or create a launch configuration.
  2. Click Live Edit. If the app is deployed in your workspace, it is redeployed to enable Live Edit mode. Otherwise, the contents of your workspace are deployed in Live Edit mode by using the specified launch configuration. Clicking the Live Edit button
  3. When redeployment finishes, the deployment status icon turns green and the phrase (running: live edit) is shown beside your launch configuration on the run bar. Live Edit enabled

When you work in Live Edit mode, changes to static files, such as HTML or CSS, can usually be seen immediately in the deployed app. If you make changes that affect Node.js source files, you can restart the app quickly, without redeployment, by clicking the restart icon The restart icon.

Debug Node.js apps

Another benefit of Live Edit mode is the Debug feature. You can edit code dynamically, insert breakpoints, step through code, restart the runtime, and more, while your app is running on Bluemix.

  1. On the run bar, click the debug icon The debug tools icon. Debug tools console
  2. Click Suspend to temporarily suspend the app so that the debugger can connect to it.
  3. Select an option to continue.

    • If you click Open Shell, a Bash shell is displayed. In the shell, you can access the container that your app is running in. You can remotely run diagnostic shell commands to administer your app.

    Bash shell

    • If you click Open Debugger, Node Inspector opens. Node Inspector is a debugger interface for Node.js apps that uses the Blink Developer Tools (formerly WebKit Web Inspector).

      Note: Node Inspector is supported on Chrome and Opera browsers only.

    Node Inspector

    Node Inspector offers many useful debugging techniques for apps:

    • Setting breakpoints and specifying trigger conditions in code
    • Disabling or enabling all breakpoints
    • Inspecting scopes, variables, and object properties
    • Displaying the value of an expression in source code by hovering over it
    • Editing variables and object properties
    • Breaking on exceptions

    For more information about Node Inspector, see these resources:

Test and debug on the command line

You can use Bluemix Live Sync for more than work in the Web IDE. You can also edit in your local environment and preview them on Bluemix. To do so, use the Bluemix Live Sync command-line tool, "bl", which synchronizes your desktop with your project workspace.

Before you begin: Download and install the Bluemix Live Sync command-line interface.

Synchronize your local environment with Bluemix

  1. Open a command-line window.
  2. Sign in to Bluemix by entering this command:

    bl login

    Enter your user ID and personal access token or your IBM id password.

    Note: Your user ID for DevOps Services can be either an IBM id or a federated ID (corporate ID). If you use federated authentication, to log in to your Bluemix Live Sync command-line client, you must use a personal access token instead of a password. If you don't use federated authentication, your IBM id and password work with all clients. For more information about creating a personal access token, see What's federated authentication and how does it affect me?

  3. View a list of your Bluemix projects:

    bl projects
  4. Synchronize your local environment with your project on Bluemix:

    bl sync projectName

    where projectName is your Bluemix app's name.

By synchronizing your local environment with Bluemix, you populate localDirectory with the files from your Node.js project. When you are finished making changes, type q to end synchronization.

Enable the Desktop Sync feature to edit code locally

The Desktop Sync feature is like Live Edit mode for the command line. To debug on the command line, you must enable the Desktop Sync feature.

  1. In another command-line window, enable the Desktop Sync feature:
    cd localDirectory
    bl start
  2. Use the launch configuration that you created in the Web IDE. After you select the launch configuration, Desktop Sync is enabled in your local environment. In the command-line window that you just opened, you can view the app's URL, the debug URL, the manage URL, and view the Bluemix Live Sync state.

  3. Refresh the browser and verify that you can see the changes that you saved to static files in the local workspace.

Disable the Desktop Sync feature

  1. In the second command-line window, enter bl stop.
  2. In the first command-line window, press q.


You learned how to create a launch configuration and deploy an app from the run bar. You also used Bluemix Live Sync to edit a Node.js project and preview changes both in the cloud and locally from the command line.

Next steps

After you test and debug your app, learn more about setting up automated build and deploy processes.