JavaScript unit tests are run in a browser against a test server which actually handles the testing process.
This server allows you to capture a browser to run tests in, loads the test targets to the captured browser, controls the testing process, and exchanges data between the browser and WebStorm,
so you can view test results without leaving the IDE.
The test server does not necessarily have to be on your machine, it can be launched right from WebStorm
through the Karma test runner.
Karma executes unit tests according to a karma.conf.js configuration file which is generated semi-automatically in the interactive mode.
Download and install Node.js. The runtime environment is required for two reasons:
The transpiledLanguage tiilType is started through Node.js.
NPM, which is a part of the runtime environment, is also the easiest way to download the transpiledLanguage tiilType.
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 transpiledLanguage tiilType and npm from any folder.
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.
In the command line mode, switch to your project directory.
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.
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.
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.
Click the Add button on the toolbar and select the Karma configuration type.
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.
Apply the changes and close the dialog box.
Launching unit tests
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.
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.