PyCharm 2021.1 Help

Run/Debug Configuration: Node.js

Run | Edit Configurations | Add New Configuration | Node.js

The following Node.js versions are supported in PyCharm 2020.3:

  • Node.js 10

  • Node.js 12

  • Node.js 14

  • Node.js 15

Learn more from Supported Node.js versions.

In this dialog, create configurations for starting the debugger together with your Node.js applications on your computer.

Before you start

  1. Download and install Node.js.

  2. Install the Node.js plugin on the Settings/Preferences | Plugins page, tab Marketplace, as described in Installing plugins from JetBrains repository.

Configuration tab

ItemDescription
Node interpreterIn this field, specify the Node.js interpreter to use. This can be a local or remote Node.js interpreter or a Node.js on Windows Subsystem for Linux. Select an interpreter from the list or click the Browse button and configure a new one in the dialog that opens.
Node parameters

In this field, type the Node.js-specific command-line options to be passed to the Node.js executable file. The most common options are:

  • Use --require coffeescript/register to have CoffeeScript files compiled into JavaScript on the fly during run.

    This mode requires that the register.js file, which is a part of the coffeescript package, is located inside your project. Therefore make sure you have the coffeescript package installed locally as described in Install the CoffeeScript compiler.

  • Use --inspect or --inspect-brk parameter when you are using Node.js v7 for Chrome Debugging Protocol support. Otherwise, by default the debug process will use V8 Debugging Protocol.

For a full list, see Node.js command-line options.

Working directoryIn this field, specify the working directory of the application. By default, the field shows the project root folder.
JavaScript file In this field, specify the path to the main file of the application that starts it (for example, bin/www for Express applications).

If you are going to debug CoffeeScript, specify the path to the generated JavaScript file with source maps. The file can be generated externally or through compilation using File Watchers. For more details, see Debugging CoffeeScript.

Application parameters In this field, type the Node.js-specific arguments to be passed to the application on start through the process.argv array.
Environment variables In this field, specify the environment variables for the Node.js executable file, if applicable. Click Browse the Browse button to the right of the field and configure a list of variables in the Environment Variables dialog, that opens:
  • To define a new variable, click the Add button and specify the variable name and value.

  • To discard a variable definition, select it in the list and click the Remove button.

  • Click OK, when ready

The definitions of variables are displayed in the Environment variables read-only field with semicolons as separators, for example:

  • NODE_PATH: A : -separated list of directories prefixed to the module search path.

  • NODE_MODULE_CONTEXTS: Set to 1 to load modules in their own global contexts.

  • NODE_DISABLE_COLORS: Set to 1 to disable colors in the REPL.

Docker container settings

Click the Browse button to open the dialog and specify the following settings:

Options
  • Publish all ports: Expose all container ports to the host. This corresponds to the option --publish-all.

  • Port bindings: Specify the list of port bindings. Similar to using the -p option with docker run.

  • Volume bindings: Use this field to specify the bindings between the special folders- volumes and the folders of the computer, where the Docker daemon runs. This corresponds to the -v option.
    See Managing data in containers for details.

  • Environment variables: Use this field to specify the list of environment variables and their values. This corresponds to the -e option. Refer to the page ENV (environment variables) for details.

  • Run options: Use this field to specify the docker command-line options.

Click Icons actions move down to expand the tables. Click Icons general add, Icons general remove, or Icons actions edit to make up the lists.

Auto configuration

Select this checkbox to have PyCharm configure the container settings. In the Automatic configuration mode:

  • PyCharm creates a new image and installs the npm modules in it.

  • PyCharm runs the container with the new image, binds your project folder to /opt/project folder in the container to ensure synchronization on update, and maps /opt/project/node_modules to the OS temporary directory.

Even with automatic configuration, you still need to bind the port on which your application is running with the port of the container. Those exposed ports are available on the Docker host’s IP address (by default 192.168.99.100). Such binding is required when you debug the client side of a Express application. In this case, you need to open the browser from your computer and access the application at the container host through the port specified in the application.

Configure port bindings

  1. Click the Browse button in the Docker Container Settings field and expand the Port bindings area in the Edit Docker Container Settings dialog that opens.

  2. Click the Add button and in the Port bindings dialog that opens, map the ports as follows:

    • In the Container port field, type the port specified in your application.

    • In the Host port field, type the port through which you want to open the application in the browser from your computer.

    • In the Host IP field, type the IP address of the Docker's host, the default IP is 192.168.99.100. The host is specified in the API URL field on the Docker page of the Settings / Preferences dialog.

    • Click OK to return to the Edit Docker Container Settings dialog where the new port mapping is added to the list.

  3. Click OK to return to the Run/Debug Configuration: Node.js dialog.

Browser / Live Edit tab

In this tab, configure the behaviour of the browser and enable debugging the client-side code of the application. This functionality is provided through a JavaScript Debug run configuration, so technically, PyCharm creates separate run configurations for the server-side and the client-side code, but you specify all your settings in one dedicated Node.js run configuration.

Item

Description

Open browserIn the field in this area, specify a project HTML file to create a correct URL to this file according to the project root to be started on the built-in web server. For example, if you choose project_root/inner_folder/index.html the resulting URL will be http://localhost:63342/project_root/inner_folder/index.html. If you select the After Launch checkbox, the browser will open this page automatically after the application starts. Alternatively you can view the same result by opening the page with this URL address in the browser of your choice manually.
After launch

Select this checkbox to automatically open the browser. From the list, select the browser to use:

  • To use the system default browser, select Default.

  • To use a custom browser, select it from the list. Note that Live Edit is fully supported only in Chrome.

  • To configure browsers, click the Browse button and adjust the settings in the Web Browsers dialog that opens. For more information, see Configure browsers.

with JavaScript debugger

Select this checkbox to enable debugging the client-side code in the selected browser.

V8 Profiling tab

In this tab, enable V8 CPU and memory profiling.

ItemDescription
Record CPU profiling infoSelect this checkbox to start logging the CPU profiling data when the application is launched. The controls in the area below become enabled. Specify the following:
  • Log folder: in this field, specify the folder to store recorded logs in. Profiling data are stored in log files isolate-<session number>.

  • One log file for all isolates (V8 instances): select this checkbox to create only one log file (and accordingly one profiling results view) for all V8 instances. Clear the checkbox to create a separate file for each instance. Node.js can create an additional V8 instance, e.g. for a debugging process.

Allow taking heap snapshotsSelect this checkbox if you are going to run memory profiling.

Logs tab

In this tab, enable showing information produced by a logging tool like morgan in the Console tab of the Run tool window. See Managing logs when running a Node.js app for details.

Common

When you edit a run configuration (but not a run configuration template), you can specify the following options:

Item

Description

Name

Specify a name for the run/debug configuration to quickly identify it when editing or running the configuration, for example, from the Run popup Alt+Shift+F10.

Allow parallel run

Select to allow running multiple instances of this run configuration in parallel.

By default, it is disabled, and when you start this configuration while another instance is still running, PyCharm suggests to stop the running instance and start another one. This is helpful when a run/debug configuration consumes a lot of resources and there is no good reason to run multiple instances.

Store as project file

Save the file with the run configuration settings to share it with other team members. The default location is .idea/runConfigurations. However, if you do not want to share the .idea directory, you can save the configuration to any other directory within the project.

By default, it is disabled, and PyCharm stores run configuration settings in .idea/workspace.xml.

Toolbar

The tree view of run/debug configurations has a toolbar that helps you manage configurations available in your project as well as adjust default configurations templates.

ItemShortcutDescription
the Add buttonAlt+InsertCreate a run/debug configuration.
the Remove buttonAlt+DeleteDelete the selected run/debug configuration. Note that you cannot delete default configurations.
CopyCtrl+DCreate a copy of the selected run/debug configuration. Note that you create copies of default configurations.
Save configurationThe button is displayed only when you select a temporary configuration. Click this button to save a temporary configuration as permanent.
Edit TemplatesView and edit the template (that is, the default run/debug configuration settings). The templates are displayed under the Templates node and used for newly created configurations.
Method up/ Method downAlt+Up/ Alt+Down

Move the selected run/debug configuration up and down in the list.

The order of configurations in the list defines the order, in which the configurations appear when you choose a run/debug configuration.

Default templates of run/debug configurations are always sorted alphabetically.

Move into new folder / Create new folder

Move into new folder / Create new folder. You can group run/debug configurations by placing them into folders.

To create a folder, select the configurations within a category, click Folder, and specify the folder name. If only a category is in focus, an empty folder is created.

Then, to move a configuration into a folder, between the folders or out of a folder, use drag or Move Up and Move Down buttons.

To remove grouping, select a folder and click Remove Configuration.

Sort configurations Click this button to sort configurations in the alphabetical order.

Before Launch

In this area, you can specify tasks to be performed before starting the selected run/debug configuration. The tasks are performed in the order they appear in the list.

ItemShortcutDescription
the Add buttonAlt+Insert

Click this icon to add one of the following available tasks:

  • Run External tool: select to run an external application. In the dialog that opens, select one or multiple applications you want to run. If it is not defined in PyCharm yet, add its definition. For more information, see External tools and External Tools.

  • Run Another Configuration: select to execute another run/debug configuration. In the dialog that opens, select the configuration to be run.

  • Launch Web Browser: select this option to have a browser started. In the dialog that opens, select the type of the browser and provide the start URL. Also, specify if you want the browser be launched with JavaScript debugger.

  • Run File Watchers: select this option to have PyCharm apply all the currently active File Watchers.

  • Run Grunt task: select this option to run a Grunt task.

    In the Grunt task dialog that opens, specify the Gruntfile.js where the required task is defined, select the task to execute, and specify the arguments to pass to the Grunt tool.

    Specify the location of the Node.js interpreter, the parameters to pass to it, and the path to the grunt-cli package.

  • Run Gulp task: select this option to run a Gulp task.

    In the Gulp task dialog that opens, specify the Gulpfile.js where the required task is defined, select the task to execute, and specify the arguments to pass to the Gulp tool.

    Specify the location of the Node.js interpreter, the parameters to pass to it, and the path to the gulp package.

  • Run npm Script: select this option to execute an npm script.

    In the NPM Script dialog that opens, specify the npm run/debug configuration settings.
  • Start React Native Bundler: select this option to run the bundler automatically, as part of a running or debugging session. by default, this is done through react-native start. If your application uses Expo, you need to run the development server via the start npm task. To do that, click Add, then in the Configure React Native dialog, choose npm script and select start from the list.

  • Compile TypeScript: select to run the built-in TypeScript compiler and thus make sure that all the changes you made to your TypeScript code are reflected in the generated JavaScript files. In the TypeScript Compile Settings dialog that opens, select or clear the Check errors checkbox to configure the behaviour of the compiler in case any errors are detected:

    • If the Check errors checkbox is selected, the compiler will show all the errors and the run configuration will not start.

    • If the Check errors checkbox is cleared, the compiler will show all the detected errors but the run configuration still will be launched.

  • Generate CoffeeScript Source Maps: select this option to generate the source maps for your CoffeeScript sources. In the dialog that opens, specify where your CoffeeScript source files are located.

  • Run Remote External tool: adds a remote SSH external tool.

the Remove buttonAlt+DeleteClick this icon to remove the selected task from the list.
EditEnterClick this icon to edit the selected task. Make the necessary changes in the dialog that opens.
Method up/ Method downAlt+Up/ Alt+DownClick these icons to move the selected task one line up or down in the list. The tasks are performed in the order that they appear in the list.
Show this pageSelect this checkbox to show the run/debug configuration settings prior to actually starting the run/debug configuration.
Activate tool window

By default this checkbox is selected and the Run or the Debug tool window opens when you start the run/debug configuration.

Otherwise, if the checkbox is cleared, the tool window is hidden. However, when the configuration is running, you can open the corresponding tool window for it yourself by pressing Alt+4 or Alt+5.

Last modified: 14 April 2021