Run/Debug Configuration: Mocha

Create: Run | Edit Configurations | | Mocha

This page describes the configuration-specific items as well as options that are common for all run/debug configurations. For more information about using this configuration, refer to Mocha.

In this dialog, create configurations for running and debugging JavaScript unit tests using the Mocha test framework.

Before you start

Download and install Node.js.
Make sure the JavaScript and TypeScript and Node.js required plugins are enabled on the Settings | Plugins page. For more information, refer to Managing plugins.

Mocha-specific configuration settings

Item	Description
Node runtime	In this field, specify the Node.js runtime to use. Choose one of the configured runtimes or click and configure a new one as described in Configuring a local Node.js runtime. If you choose the `Project` alias, IntelliJ IDEA will automatically use the project default runtime from the Node runtime field on the JavaScript Runtimes page.
Node options	In this field, type the Node.js-specific command-line options to be passed to the Node.js executable file. For more information, refer to Node Parameters.
Working directory	In this field, specify the working directory of the application. By default, the Working directory field shows the project root folder. To change this predefined setting, specify the path to the desired folder.
Environment variables	In this field, specify the custom environment variables for the Node.js executable file. The definitions of variables are displayed in the Environment variables field with semicolons (`;`) as separators, for example: `NODE_PATH` A list of additional directories to search when resolving modules. To separate directories in a list, use colon (`:`) on macOS or Linux, use semicolon (`;`) on Windows. `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. Alternatively, click Browse to the right of the field and configure a list of variables in the Environment Variables dialog, that opens: Use , , and buttons to manage the list of custom variables. The dialog also shows a list of available system environment variables. Clear the Include system environment variables checkbox if you don't want to use the system environment variables for the current configuration. Click OK, when ready.
Mocha package	In this field, specify the Mocha installation home /npm/node_modules/mocha. If you installed Mocha regularly through the Node Package Manager, IntelliJ IDEA detects the Mocha installation home itself. Alternatively, type the path to executable file manually, or click Browse and select the location in the dialog, that opens.
User interface	From this list, choose the interface according to which the tests in the test folder are written. IntelliJ IDEA will recognize only tests that comply with the chosen interface. If during test execution IntelliJ IDEA runs against a test of another interface, the test session will be canceled with an error. This means that all the tests in the specified test folder must be written according to the same interface and this interface must be chosen from the list.
Extra Mocha options	In this field, specify additional Mocha command-line options. For example, add a `--watch` flag to turn on the autotest-like runner. As a result, any test in the current run configuration restarts automatically on changing the related source code, without clicking the Rerun button .
Tests	In this area, specify the tests to be executed. The available options are: All in directory: choose this option to run all the tests from the files stored in a folder and specify the path to this folder in the Test directory field. To look for tests in the subfolders under the specified directory, select the Include subdirectories checkbox. File patterns: choose this option to look for tests in all the files with the names that match a certain. Specify the mask in the Test file patterns field using glob patterns, for example: .test.js If the files with tests are stored in a separate folder, for example, test, specify the path to this folder in the pattern relative to the working directory: ./folder1/folder2/test/.test.js Test file: choose this option to run only the tests from one file and specify the path to this file in the Test file field. Suite: choose this option to run individual suites from a test file and specify the path to this file in the Test file field. Click in the Suite name field and configure a list of suites to run using the and buttons. Test: choose this option to run individual tests from a test file and specify the path to this file in the Test file field. Click in the Test name field and configure a list of tests to run using the and buttons.
Docker container settings	This read-only field shows port and volume bindings. Click to open the command preview. This field only appears when a Docker-based remote interpreter is selected.
Docker Compose	In this area, specify the commands and options to be passed to Docker Compose. Accept the default settings or click and specify custom ones, for example, custom Docker Compose flags, like `--rm` or `--service-ports`. Learn more from the Docker official website. Check the Command Preview. This field only appears when a remote runtime via Docker Compose is selected.

Common settings

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 configuration to quickly identify it among others when editing or running.
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 IntelliJ IDEA stores run configuration settings in .idea/workspace.xml.

Item

Description

Name

Specify a name for the run configuration to quickly identify it among others when editing or running.

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 IntelliJ IDEA stores run configuration settings in .idea/workspace.xml.

Stepping tab

On this tab, specify the stepping options.

Some scripts (for example, methods of standard Java classes like System) are skipped by Step into as you normally might not need to debug them. This list can be fine-tuned on the Build, Execution, Deployment | Debugger | Stepping page of the Settings dialog (Ctrl+Alt+S) .

Open the run/debug configuration to launch a debugging session with and switch to the Stepping tab.
To suppress automatic Smart Step Into, clear the Always do smart step into checkbox.
To skip scripts from the ignoreList field of the sourcemaps, select the Ignore known third party scripts specified in source maps checkbox.
The older Chrome-specific field name x_google_ignoreList is deprecated but may still be recognized when the ignoreList field is absent. Learn more from the source map specification.
To suppress stepping into custom scripts, select the Do not step into scripts with a URL matching the patterns below checkbox and expand the default list of such scripts below. Use *, ?, ** and !.

Pattern syntax

The following characters are supported in patterns:

An asterisk * matches zero or more characters except a slash /. Use this character inside a single path part.
A question mark ? matches exactly one character except a slash /.
A double asterisk ** as a whole segment matches zero or more path segments. Its meaning depends on its position:
- As the first part, it matches any leading symbols.
- As the last part, it matches any trailing symbols.
- In the middle, it matches one or more parts. For example, a/**/b matches a/x/b and a/x/y/bbut not a/b.
A trailing double asterisk ** at the end of the last segment (not on its own a full segment, for example, foo**) matches any suffix after that segment. For example, foo** matches foo, foobar, and foo/bar.
A pattern that starts with and exclamation mark ! negates the given pattern and modifies the patterns added before it in the list. It does not add a new pattern of its own.

Example 1

In the pattern list ["**/*.ts", "!**/*.test.ts"], the first glob matches every .ts file. The second pattern modifies the first glob to exclude every .test.ts file from match.

Example 2

A passed URL is split into parts by means of a slash /. Accordingly, **/node_modules/** is split as follows::

Double asterisk ** matches any path before the node_modules segment.
node_modules matches against a node_modules in the URL.
Double asterisk ** matches anything trailing.

As a result, the pattern **/node_modules/** matches any URL that contains node_modules.

Keep in mind that the URLs of the scripts are matched against the whole pattern. If we remove the second double asterisk **, the pattern will match any URL that ends with node_modules of which there will likely be zero.

Example 3

Skip the second double asterisk ** to match against any pattern that ends with a particular filename.

**/app.js matches all URLs that end with app.js.
The following pattern list will ignore all scripts in node_modules except those named app.js.
**/node_modules/** !**/app.js

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.

Item	Shortcut	Description
	`Alt+Insert`	Create a run/debug configuration.
	`Alt+Delete`	Delete the selected run/debug configuration. Note that you cannot delete default configurations.
	`Ctrl+D`	Create a copy of the selected run/debug configuration. Note that you create copies of default configurations.
		The button is displayed only when you select a temporary configuration. Click this button to save a temporary configuration as permanent.
		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 , 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 and buttons. To remove grouping, select a folder and click .
		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.

Item	Shortcut	Description
	`Alt+Insert`	Click this icon to add one of the following available tasks: 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 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 IntelliJ IDEA yet, add its definition. For more information, refer to External tools and External tools settings. Run Another Configuration: select to execute another run/debug configuration and wait until it finishes before starting the current configuration. If you want to run several configurations in parallel, use a compound run/debug configuration. Build: select to compile the specified module. The Build Module command will be executed. If an error occurs during compilation, IntelliJ IDEA won't attempt to start the run/debug configuration. Build Project: select to compile the entire project. The Build Project command will be executed. If an error occurs during compilation, IntelliJ IDEA won't attempt to start the run/debug configuration. Build, no error check: the same as the Build option, but IntelliJ IDEA will try to start the run/debug configuration irrespective of the compilation results. Build Artifacts: select this option to build an artifact or artifacts. In the dialog that opens, select the artifact or artifacts that should be built. Run Remote External tool: adds a remote SSH external tool. 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 runtime, 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 runtime, the parameters to pass to it, and the path to the gulp package. Run Maven Goal: select this option to run a Maven goal. In the dialog that opens, select the goal to be run. 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. 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 Rake task: add a Rake task to be executed prior to running or debugging. To choose a Rake task, click the browse button , and select the desired task from the list of available tasks. Note that code completion is available here. Run JRuby compiler: choose this option to execute JRuby compiler with the specified target path, compiler process heap size, and command line parameters (if any).
	`Alt+Delete`	Click this icon to remove the selected task from the list.
	`Enter`	Click this icon to edit the selected task. Make the necessary changes in the dialog that opens.
	`Alt+Up` `Alt+Down`	Click 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 page		Select 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`.

02 September 2026