I've been going kind of crazy covering a particular Drupal site I'm building in Behat tests—testing every bit of core functionality on the site. In this particular case, a feature I'm testing allows users to upload arbitrary files to an SFTP server, then Drupal shows those filenames in a streamlined UI.

I needed to be able to test the user action of "I'm a user, I upload a file to this directory, then I see the file listed in a certain place on the site."

These files are not managed by Drupal (e.g. they're not file field uploads), but if they were , I'd invest some time in resolving this issue in the drupalextension project: "When I attach the file" and Drupal temporary files .

Since they are just random files dropped on the filesystem, I needed to:

1. Create a new step definition
2. Track files that are created using that step definition
3. Add code to make sure files that were created are cleaned up

If I just added a new step definition in my FeatureContext which creates the new files, then subsequent test runs on the same machine would likely fail, because the test files I created are still present.

Luckily, Behat has a mechanism that allows me to track created resources and clean up after the scenario runs (even if it fails), and those in Drupal-land may be familiar with the naming convention—they're called hooks .

In this case, I want to add an @AfterScenario hook which runs after any scenario that creates a file, but I'm getting a little ahead of myself here.

Create a new step definition

Whenever I want to create a new step definition, I start by writing out the step as I want it, in my feature file:

When I add file "test.txt" to the "example" folder

Now I run the scenario using Behat, and Behat is nice enough to generate the stub function I need to add to my FeatureContext in it's output:

--- Drupal\FeatureContext has missing steps. Define them with these snippets:

    /**
     * @When I add file :arg1 to the :arg2 folder
     */
    public function iAddFileToTheFolder($arg1, $arg2)
    {
        throw new PendingException();
    }

I copy that code out, drop it into my FeatureContext , then change things to do what I want:

  /**
   * @When I add file :file_name to the :folder_name folder
   */
  public function iAddFileToTheFolder($file_name, $folder_name) {
    $file_path = '/some/system/directory/' . $folder_name . '/' . $file_name;
    $file = fopen($file_path, 'w');
    fwrite($file, '');
    fclose($file);
  }

Yay, a working Behat test step! If I run it, it passes, and the file is dropped into that folder.

But if I run it again, the file was already there and the rest of my tests may also be affected by this rogue testing file.

So next step is I need to track the files I create, and make sure they are cleaned up in an @AfterScenario .

Track files created during test steps

At the top of my FeatureContext , I added:

  /**
   * Keep track of files added by tests so they can be cleaned up.
   *
   * @var array
   */
  public $files = [];

This array tracks a list of file paths, quite simply.

And then inside my test step, at the end of the function, I can add any file that is created to that array:

  /**
   * @When I add file :file_name to the :folder_name folder
   */
  public function iAddFileToTheFolder($file_name, $folder_name) {
    $file_path = '/some/system/directory/' . $folder_name . '/' . $file_name;
    $file = fopen($file_path, 'w');
    fwrite($file, '');
    fclose($file);
    $this->files[] = $file_path;
  }

That's great, but next we need to add an @AfterScenario hook to clean up the files.

Make sure the created files are cleaned up

At the end of my feature context, I'll add a cleanUpFiles() function:

  /**
   * Cleans up files after every scenario.
   *
   * @AfterScenario @file
   */
  public function cleanUpFiles($event) {
    // Delete each file in the array.
    foreach ($this->files as $file_path) {
      unlink($file_path);
    }

    // Reset the files array.
    $this->files = [];
  }

This @AfterScenario is tagged with @file , so any scenario where I want the files to be tracked and cleaned up, I just need to add the @file tag, like so:

@myfeature
Feature: MyFeature

  @api @authenticated @javascript @file
  Scenario: Show changed files in selection form using Git on Site page.
    Given I am logged in as a user with the "file_manager" role
    When I am on "/directory/example"
    Then I should see the text "There are no files present in the example folder."
    And I should not see the text "test.txt"
    When I add file "test.txt" to the "example" folder
    And I am on "/directory/example"
    Then I should see the text "text.txt"

And that is how you do it. Now no matter whether I create one file or a thousand, any scenario tagged with @file will get all its generated test files cleaned up afterwards!