Regression and unit tests

From LimeSurvey Manual

Warning : Every time you discover a new bug, you should add a regression test to make sure it does not appear again.
Warning : NEVER run tests on a production system. The tests WILL modify the database.
Hint: Always make sure new code follows the PSR-2 standard for PHP. Use codesniffer and mess detector to catch common bugs and style fixes in your code.

Since LimeSurvey 2.65.6 you have the possibility to add unit tests to LimeSurvey.

Since LImeSurvey LS 3, we use chromedriver and Facebook web driver to test with the browser from PHPUnit.


In an ideal world, a regression test is added every time a new bug is discovered. That way you make sure you never have to fix the same bug twice.



  1. To enable unit testing, you have to issue the command
    $ touch enabletests
    in the LimeSurvey root folder.
  2. To install Facebook web driver, run
    composer install
  3. Install phpunit on your machine (OBS: Don't use the old phpunit version in Ubuntu apt).
  4. Install node (needed for EM tests).
  5. Install the chromedriver.
  6. Run tests with
    $ PASSWORD=adminpassword DOMAIN=your_limesurvey_domain php phpunit-<version>.phar
    PASSWORD is the admin user password (defaults to "password")
    DOMAIN is the URL to your localhost LimeSurvey installation, e.g. "localhost/limesurvey" or "limesurvey.localhost".






After all steps for the installation are completed, you should be able to write

$ PASSWORD=adminpassword DOMAIN=your_limesurvey_domain phpunit

in the LimeSurvey root folder to run the tests.

If LimeSurvey is installed on your web root, use "DOMAIN=localhost".

This is an example of the output:

 $ phpunit
 PHPUnit 5.6.2 by Sebastian Bergmann and contributors.

 ....                                                                4 / 4 (100%)

Time: 713 ms, Memory: 14.00MB

OK (4 tests, 24 assertions)

You can get some more information if you use the switch --testdox:

$ phpunit --testdox
PHPUnit 5.6.2 by Sebastian Bergmann and contributors.

 [x] Q 1

 [x] Wrong input
 [x] Correct date format
 [x] Q 1

During testing, you might want to use --group <test group> and/or --stop-on-failure.

What can be tested?

Right now, there are tests for the expression manager, qanda and updatedb helper. The Selenium driver makes it also possible to test the full browser experience, including JavaScript.

What should be tested?

Everything that can be reported as a bug should be tested, but especially critical is of course the relation between user input and database, that is, that the correct answer is saved.

Adding a test

First of all, make sure to head over to the phpunit web site and read the introduction.

When done with that, I will assume you want to add a new test for a question type. Tests for questions are stored in folder tests/questions.

You should create a minimal survey to reproduce your bug. Export it as an lss file and put it in tests/data/surveys. Then create a class for your test. Name the file the same as the class, like "DateTimeForwardBackTest.php". The class name must end with "Test", so phpunit can find it.

Inside the class you might want to add code to import and delete the survey. I usually do this class-wide, which means that the survey gets imported when the class is loaded and then deleted when all tests in the class is done (whether failed or successfully).

The static methods setupBeforeClass and teardownAfterClass is used to setup and teardown the test fixture, respectively. You can read more about fixtures in the phpunit manual.

Let's list what we know so far:

namespace ls\tests;

use PHPUnit\Framework\TestCase;

 * @since 2017-06-16
 * @author Olle Haerstedt 
class DateTimeDefaultAnswerExpressionTest extends \TestCase
  public static function setupBeforeClass()
    // Init stuff

  public static function teardownAfterClass()
    // Tear down what you setup before.

To test with Selenium and the Facebook web driver, check out the wiki page on github.



All tests are run automatically after each commit using Travis continuous integration.