Running and debugging Node.js
warning
Do not set up a working directory for the default Run/Debug Configurations listed under the Templates node. This may lead to unresolved targets in newly created Run/Debug Configurations.
Go to . Alternatively, select Edit Configurations from the list on the toolbar.
In the Edit Configurations dialog that opens, click the Add button (
) on the toolbar and select Node.js from the list. The Run/Debug Configuration: Node.js dialog opens.Specify the Node.js interpreter to use.
If you choose the Project alias, PyCharm will automatically use the project default interpreter from the Node interpreter field on the Node.js page . In most cases, PyCharm detects the project default interpreter and fills in the field itself.
You can also choose another configured local or remote interpreter or click
and configure a new one.In the JavaScript File field, specify the path to the main file of the application that starts it (for example, bin/www for Express applications).
Optionally:
Specify the Node parameters that customize the start of Node.js. For example, you may want to enable an experimental Node.js feature or pass another option. For more information, refer to the Node.js official website.
In the Application parameters field, specify the Node.js-specific arguments to be passed to the application on start through the process.argv array.
To open the application in the browser automatically, configure a before-launch task. Click
to expand the Before launch area, click , and select Launch Web Browser from the list. In the dialog that opens, specify the URL of the application starting page, for example, localhost:3000for Express applications, and the browser to use.
Create a run/debug configuration as described above or modify an existing one and click Run in the dialog.
Alternatively, select the newly created run configuration from the list on the main toolbar and click
. 
The application starts, and the Run tool window opens showing the application output.
Create a Node.js run/debug configuration as described above and go to the Logs tab.
Click
next to the Log files to be shown in console field which lists the available log files (if any).In the Edit Log Files Aliases dialog that opens, type the alias name to show in the list of log entries and specify the location of the log file. Select whether you want to show all files that this pattern covers or only the last one.
Click OK to return to Node.js Run/Debug Configuration dialog, where the new log file is added to the list. Select the Is Active checkbox next to it. To skip the previous content, select the Skip Content checkbox.
Optionally:
To enable saving the Process Console output to a log file, select the Save console output to file checkbox and specify the file location.
Choose when you want the Process Console shown.
Set the breakpoints in the code where necessary.
Create a Node.js run/debug configuration as described above.
To open the application in the browser automatically, configure a before-launch task. Click
to expand the Before launch area, click , and select Launch Web Browser from the list. In the dialog that opens, specify the URL of the application starting page, for example, localhost:3000for Express applications, and the browser to use.tip
If necessary, PyCharm can generate a JavaScript Debug configuration and start it automatically together with the Node.js configuration as described in Debugging the server- and the client-side code.
Select the newly created Node.js configuration from the Select run/debug configuration list on the toolbar and click the Debug button (
) next to the list. 
The Debug tool window opens.
Perform the steps that will trigger the execution of the code with the breakpoints. For example, navigate from the starting page of your application to another page in the browser.
Switch to PyCharm, where the controls of the Debug tool window are now enabled. Proceed with the debugging session — step through the breakpoints, switch between frames, change values on-the-fly, examine a suspended program, evaluate expressions, and set watches.
Run your application with an
--inspector--inspect-brkflag. You can do that in several ways, for example:Open the embedded Terminal () and, type:
node --inspect-brk <path to the starting page of your application relative to the project root>Launch a script from package.json or from the npm tool window. For more information, refer to Run and debug scripts.
Depending on the action you select from the list, the output will be shown in the Run or in the Console tab of the Debug tool window.
The Terminal, the Run tool window, or the Console tab of the Debug tool window shows an information message
Debugger listening <host>:<port>, the default port is9229. To start debugging, hold and click the link.PyCharm starts a debugging session with an automatically generated Attach to Node.js/Chrome configuration.
note
Alternatively, copy the port number from the
Debugger listening <host>:<port>message and paste it later in the Attach to Node.js/Chrome configuration.
Set the breakpoints as necessary.
Select from the main menu, then click
in the Edit Configuration dialog that opens, and select Attach to Node.js/Chrome from the list. The Run/Debug Configuration: Attach to Node.js/Chrome dialog opens.Specify the host where the target application is running and the port passed to
--inspector--inspect-brkwhen starting the Node.js process to connect to. Copy the port number from the information messageDebugger listening <host>:<port>in the Terminal tool window or in the Run tool window that controls the running application.
warning
Make sure this port is different from the port on which the application is running. The default port is 9229.
tip
Optionally: specify the remote paths for the project folders in the Remote URLs of local files area. This is helpful if the root folder of the running application is different from the name of you PyCharm project root folder.
In the Attach to area, select Chrome or Node.js > 6.3 started with --inspect.
Select the newly created Attach to Node.js/Chrome configuration from the Select run/debug configuration list on the toolbar and click the Debug button (
) next to the list. The Debug tool window opens.Perform the actions that will trigger the code at the breakpoint. Control over the debugging session returns to PyCharm.
Switch to PyCharm. In the Debug tool window, step through the breakpoints, switch between frames, change values on-the-fly, examine a suspended program, evaluate expressions, and set watches.
tip
For more information, refer to Running and debugging scripts.
Set the breakpoints in your code as necessary.
Create a new Attach to a Node.js/Chrome configuration as described in Debugging a running Node.js application and select the Reconnect automatically checkbox.
Usually, you don’t need to change the port in the configuration
9229because it’s the default port the debugger is listening on. But you can double-check what port is used in the message logged when you run the app in the debug mode.
Select the newly created Attach to Node.js/Chrome configuration from the Select run/debug configuration list on the toolbar and click the Debug button (
) next to the list. The debugger stops at the breakpoints that you put in your code in PyCharm.Now, every time you make any changes to the code and save them , nodemon will automatically reload the application, and the debugger will automatically re-attach to the restarted process.