How can I get module configuration for testing

Question

I write tests for a form in a custom module using Drupal\simpletest\WebTestBase. I want to test, if the module settings are displayed in the configuration form. But the problem is, that I can not get the saved settings:

$config = $this->config('mymodule.settings');
debug($config->get(), 'Configuration object'); // Returns an empty array

I have found, that the same problem is e.g. in the demo module described in an article on Sitepoint, see: https://github.com/upchuk/d8-demo-modules/blob/master/demo/src/Tests/DemoTest.php#L59

E.g. $config->get('demo.email_address') returns always ''.

The tests seem to work well, but when I add debug($config->get()), then I also receive an empty array. It means, that all the test cases use empty variables and return false positive results.

I have also tried:

debug(\Drupal::config('mymodule.settings')->get()); // Empty array
debug(\Drupal::configFactory()->getEditable('mymodule.settings')->get()); // Empty array
debug(\Drupal::config('system.site')->get()); // Correct array with site settings

---

The module and the form are working correctly and all the settings are stored in the database.

Answer 1

The tests do not care about the settings, which are saved in the database. They work with settings in config/import/mymodule.settings.yml

The file can look like this:

var1: 'Some text'
var2: 1
var3: http://example.org

More info: https://www.drupal.org/docs/8/creating-custom-modules/include-default-configuration-in-your-drupal-8-module