Running Unit Tests on Karma

Before you start

1. Download and install Node.js. The runtime environment is required for two reasons:
   • The Karma test runner is started through Node.js.
   • NPM, which is a part of the runtime environment, is also the easiest way to download the Karma test runner.

   If you are going to use the command line mode, make sure the path to the parent folder of the Node.js executable file and the path to the npm folder are added to the PATH variable. This enables you to launch the Karma test runner and npm from any folder.

2. Make sure the Karma test runner is installed as described in Preparing to Use Karma Test Runner.
3. Install and enable the NodeJS repository plugin as described in Installing, Updating and Uninstalling Repository Plugins and Enabling and Disabling Plugins.
4. Install and enable the Karma repository plugin. The plugin is not bundled with IntelliJ IDEA, but it can be installed from the JetBrains plugin repository as described in Installing, Updating and Uninstalling Repository Plugins and Enabling and Disabling Plugins.

Generating a Karma configuration file

Karma executes unit tests according to a karma.conf.js configuration file which is generated semi-automatically in the interactive mode. The instruction below ensures successful creation of a consistent configuration file karma.conf.js which in its turn ensures successful execution of the tests in your project. For more details, see http://karma-runner.github.io/0.10/config/configuration-file.html.

1. In the command line mode, switch to your project directory.
2. Type the following command at the command line prompt:
   karma init

   If Karma does not start, check the installation: the parent folder or the Karma executable file should be specified in the PATH variable.

3. Answer the questions to specify the following basic settings:
   • The testing framework to use.
   • The browsers to be captured automatically.
   • The patterns that define the location of test files to be involved in testing or excluded from it, for example, src/*.js and test/*.js. For more details, see http://karma-runner.github.io/0.10/config/files.html.

Creating a Karma run configuration

1. Open the Run/Debug Configuration dialog box by doing one of the following:
   • On the main menu, choose Run | Edit Configurations.
   • Open the test file in the editor, and then choose Create <file name> on the context menu.
   • Select the test file in the Project tool window, and then choose Create <file name> on the context menu of the selection.
2. Click the Add button on the toolbar and select the Karma configuration type.
3. In the dialog box that opens, specify the location of the Node.js and Karma executable files and the path to the karma.conf.js configuration file.
4. Apply the changes and close the dialog box.

Launching unit tests

1. To launch the tests according to a run configuration, select the Karma run/debug configuration from the list on the main toolbar. Then click the Run button   to the right of the list.
2. The Karma test server starts automatically without any steps from your side. View and analyze messages from the test server in the Karma Server tab of the Run tool window.
3. Monitor test execution in the Test Runner tab of the Run tool window as described in Monitoring and Managing Tests.