You can repeat your test session without leaving your test runner tab of the Run tool window. The tests are performed again using the same run configuration as in the initial run.
Rerun a testing session
Press Ctrl+F5 or click the Rerun button on the toolbar of Test Runner tab.
Note that you can rerun the tests automatically.
Rerun failed tests
In the Test Runner tab, click the Rerun Failed Tests button on the toolbar.
Rerunning tests automatically
WebStorm lets you rerun run/debug configuration of a test automatically, if the source code has been changed. To enable autotest-like runner facility, make sure that the Toggle auto-test button in the Run toolbar of the Test Runner tab is pressed.
For Cucumber.js, Karma, JSTestDriver, and Protractor, press the Toggle auto-test button on the Run toolbar of the Test Runner tab.