Writing unit tests within the IntelliJ IDE
A quick guide to writing unit tests for the demonstration project,
java-demo, using the Diffblue Cover IntelliJ plugin.
java-demo application is a simple result-checker for the traditional game of "Tic Tac Toe" (or "Noughts and Crosses") which can be found at https://github.com/diffblue/java-demo.
Start IntelliJ without a project loaded to see a welcome screen:
Git from the
Check out from Version Control option. Enter the
java-demo url into the repository box, selecting an appropriate location for the project.
Once it has been successfully cloned, expand the
java-demo section under
Project to see the source tree.
Writing new tests
java-demo contains one existing test class,
In order to generate new tests for a class which is not currently covered, select the
TicTacToe class in the
Project tool window. Right-click * and select the
Write Tests option from the menu.
The plugin builds the project before analyzing the code and creating the tests. Once the project has been built, click the progress bar at the bottom of the screen to open a pop-up window.
The progress window will show the different stages that the analysis is going through. While the code is being analyzed, it is possible to view current progress, but with
java-demo that will be a very short time-frame.
Once the new tests have been created, they will be automatically integrated into the project under
* Note that it is also possible to
Write Tests by right-clicking the following:
- individual classes from within the source editor
- individual methods from within the source editor
- individual classes from the tab at the top of the source file
- individual methods from within their classes in the
Show Membershas been selected after right-clicking on the
Elsewhere within the IDE, for example in test classes or non-Java files, the
Write Tests feature is disabled.
Running the tests
After Diffblue Cover has written tests for your project, they will be automatically integrated into your test suite.
Tests created by Diffblue Cover make use of the JUnit testing framework so
junit is included in the
java-demo project dependencies in the
Select the new
TicTacToeTest class in the project explorer, right-click and
This will then show the results of the JUnit run: