Automated testing


Acquia will end support for BLT on December 31, 2024. For more information on how to replace your BLT implementation with updated functionality, see You don’t need BLT on Acquia Cloud.

Software testing has been around for decades, and it has been proven to provide many crucial benefits, including the following:

  • Reducing the number of bugs and regressions.

  • Increasing project velocity (in the long run).

  • Improving accuracy of scheduling estimates.

  • Saving time and money.

  • Increasing user trust and satisfaction.

You should use automated testing. Don’t fall prey to common rationalizations and excuses relating to insufficient time, money, or resources. Time spent developing tests is repaid ten-fold.

That being said, two important pitfalls should be acknowledged:

  • It’s possible to do automated testing incorrectly such that it’s too expensive.

  • It’s possible to write automated tests that have little value.

To avoid these pitfalls, follow the best practices outlined in the following sections.

Test directory structure

From BLT 12.x, automated testing functionality is moved to plugins. Therefore, you must add plugins by running one or more of the following commands:

composer require acquia/blt-behat
composer require acquia/blt-drupal-test

This directory contains all projects tests, grouped by testing technology. For all configuration related to builds that actually run these tests, see the blt directory.

├── behat - contains all Behat tests
│    ├── features
│    │   ├── bootstrap
│    │   └── Example.feature
│    ├── behat.yml - contains behat configuration common to all behat
|    |               profiles
│    └── integration.yml - contains behat configuration for the
|                          integration profile, which is used to run
|                          tests on the integration environment
└── phpunit - contains PHPUnit tests for the project (Drupal PHPUnit
              tests should reside within a given Drupal module)

Additional technologies (some of which won’t be supported by BLT) can also have their tests bundled in the tests folder for convenience (for example, tests/jmeter).

BLT also supports the bundling and execution of phpunit tests from locations outside of the tests folder. For additional information, see the PHPUnit configuration section of this page.

Executing tests

Before attempting to execute any tests, verify that Composer dependencies are built by running composer install in the project root directory.

The following testing commands are available for use:

  • blt tests:all

  • blt tests:behat:run

  • blt tests:phpunit:run

  • blt tests:drupal:run

  • blt tests:security:check:updates

  • blt tests:security:check:composer

Modifying test targets

For information about overriding default configuration values, see Extending and overriding BLT.

For more information on the commands, run the following:

  • ./vendor/bin/phpunit --help

  • ./vendor/bin/behat --help


The high-level purpose of BDD is to create a strong connection between business requirements and the actual tests. Behat tests should mirror ticket acceptance criteria as closely as possible.

Consequently, proper Behat tests should be written using business domain language. The test should be comprehensible by the stakeholder and represent a clear business value. It should represent a typical user behavior and need not be an exhaustive representation of all possible scenarios.

See referenced materials for more information on BDD best practices.

Testing individual features or scenarios

To execute a single feature:

blt tests:behat:run -D behat.paths=${PWD}/tests/behat/features/Examples.feature
# Relative paths are assumed to be relative to tests/behat/features.
blt tests:behat:run -D behat.paths=Examples.feature

To execute a single scenario:

blt tests:behat:run -D behat.paths=${PWD}/tests/behat/features/Examples.feature:4
# Relative paths are assumed to be relative to tests/behat/features.
blt tests:behat:run -D behat.paths=Examples.feature:4

In the previous command, 4 is the line number of the scenario in the feature file.

To execute the tests directly (without BLT) see the following examples:

./vendor/bin/behat -c tests/behat/local.yml tests/behat/features/Examples.feature -p local


Configuration for the BLT Behat commands is stored in the behat configuration variable. You can modify the behavior of the BLT tests:behat:run target by customizing this configuration. For more information about overriding configuration variables, see Extending and overriding BLT.

Multisite or Site Factory applications may need to modify the behat configuration variable on a per-site basis by following the multisite variable override instructions.

Behat’s own configuration is defined in the following files:

  • tests/behat/behat.yml

  • tests/behat/example.local.yml

  • tests/behat/local.yml

Screenshots for failed steps

BLT includes the Behat ScreenshotExtension, configured by default to store a screenshot of any failed step locally. You can configure the extension globally under the Bex\Behat\ScreenshotExtension key in tests/behat/behat.yml, or override locally inside tests/behat.local.yml.

Review the ScreenshotExtension documentation to discover how to change where images are saved, disable the extension, or change the screenshot-taking mode.

Best practices

  • Behat tests must be used behaviorally; for example, they must use business domain language.

  • Each test should be isolated; for example, it shouldn’t depend on conditions created by another test. In practice, this means:

    • Resetting testing environment with CI after test suite runs.

    • Defining explicit cleanup tasks in features.

Common mistakes

  • Writing Behat tests that don’t use business domain language.

  • Tests are not sufficiently isolated. Making tests interdependent diminishes their value.

  • Writing tests that are exhaustive of all scenarios rather than representative of a typical scenario.

  • Writing Behat tests when a unit test should be employed.


  • Google Chrome is missing: BLT expects Google Chrome (more specifically, the google-chrome binary) to be available on the local computer. If you are using a Mac and Chrome is installed, you should be fine. If you run BLT in another Linux environment, install chromium-driver.

  • Spotting bad configuration: To troubleshoot your Behat setup, be sure to run blt doctor --site=mysite.local to try to locate any obvious issues.

  • Multisite and ACSF issues: When you must run tests with any authenticated user role, you must uninstall simplesamlphp_auth, else, Behat tests will hang. When ready, run blt behat --site=mysite.local from the project root. If running Behat tests fail, then it means you either have issues with your BLT or Behat installation or there’s an issue with tests themselves.


Unit and functional testing

Best practices

  • Tests shouldn’t contain any control statements.

  • Be careful to make both positive and negative assertions of expectations.

Common mistakes

  • Writing unit tests that are not independent.

  • Making unit tests too large. Tests should be small and granular.

  • Asserting only positive conditions. Negative assertions should also be made.



The tests configuration variable has following properties:

  • reports.localDir: Directory used to save testing reports on local environments.

  • reports.remoteDir: Directory used to save testing reports on remote environments.

  • run-server: Whether or not to launch the Drush server for testing.

  • server.port: The Drush run-server port; default is 8888.

  • server.url: The URL of Drush server; default is

  • selenium.port: Port for Selenium; default is 4444.

  • selenium.url: URL of Selenium; default is

  • chrome.port: Port for chrome browser; default is 9222.

  • chrome.args: Args for chrome browser; default is null.

  • chromedriver.port: Port for chromedriver WebDriver for Chrome; default is 9515.

  • chromedriver.args: Args for chromedriver WebDriver for Chrome; default is null.


Project level, functional PHPUnit tests are included in tests/phpunit. Any PHPUnit tests that affect specific modules or application level features should be placed in the same directory as that module or feature code, not in this directory.

You can customize the tests:phpunit:run command by modifying your BLT configuration for the tests:phpunit key.

Each row under the tests:phpunit key should contain a combination of the following properties:

  • bootstrap: A “bootstrap” PHP file run before the tests.

  • class: The class name for the test.

  • config: Path to either the Core phpunit configuration file (docroot/core/phpunit.xml.dist) or a custom one. If left blank, no configuration will be loaded with the unit test.

  • debug: If true, will display debugging information.

  • directory: Directory to scan for tests.

  • exclude: Run tests excluding any tagged with this @group.

  • file: The source file that declares the class provided in class.

  • filter: Allows text filter for tests.

  • group: Run tests only tagged with a specific @group.

  • path: The directory where the phpunit command will be run from.

  • printer: The TestListener implementation to use.

  • stop-on-error: If true, will stop execution upon first error.

  • stop-on-failure: If true, sill stop execution upon first error or failure.

  • testdox: If true, report test execution progress in TestDox format.

  • testsuite: Run tests that are part of a specific @testsuite.

  • testsuites: (array) Run tests from multiple @testsuite``s (takes precedence over ``testsuite).

For additional information, see the PHPUnit documentation.

    - # Run BLT"s example test.
      path: '${repo.root}/tests/phpunit'
      config: '${docroot}/core/phpunit.xml.dist'
      class: 'ExampleTest'
      file: 'ExampleTest.php'

Testing Drupal with PHPUnit

Each row under the tests:drupal key should contain a combination of the following properties (see Drupal’s core/phpunit.xml.dist for additional details):

  • test-runner: Whether to run Drupal tests with PHPUnit (phpunit) or Drupal’s script (run-tests-script).

  • sudo-run-tests: Whether or not to use sudo when running Drupal tests.

  • web-driver: WebDriver to use for running Drupal’s functional JavaScript tests (only chromedriver is supported).

  • browsertest-output-directory: Directory to write output for browser tests (value for BROWSERTEST_OUTPUT_DIRECTORY).

  • apache-run-group: Unix user used for tests (value for APACHE_RUN_USER).

  • apache-run-user: Unix group used for tests (value for APACHE_RUN_GROUP). If sudo-run-tests:true, this is used to run testing commands as sudo -u www-data -E ./vendor/bin/phpunit {...}.

  • mink-driver-args: Driver args to mink tests (value for MINK_DRIVER_ARGS).

  • mink-driver-args-webdriver: Driver args to webdriver tests (value for MINK_DRIVER_ARGS_WEBDRIVER).

  • mink-driver-class: Driver class for mink tests (value for MINK_DRIVER_CLASS).

  • simpletest-base-url: Base URL of Simpletest (value for SIMPLETEST_BASE_URL).

  • simpletest-db: Connection string Simpletest database (value for for SIMPLETEST_DB).

  • symfony-deprecations-helper: Setting to disabled disables deprecation testing completely (value for SYMFONY_DEPRECATIONS_HELPER).

  • phpunit: Tests to run using Drupal’s implementation of PHPUnit. This requires Drupal to be installed.

  • drupal-tests: Tests to run with Drupal’s script.

      - # Run Drupal' unit, kernel, functional, and functional-javascript testsuites for the action module.
        path: '${docroot}/core'
        config: ${docroot}/core/phpunit.xml.dist
          - 'unit'
          - 'kernel'
          - 'functional'
          - `functional-javascript`
        group: action
      - # Run all tests in the custom modules directory.
        path: '${docroot}/core'
        config: ${docroot}/core/phpunit.xml.dist
        directory: ${docroot}/modules/custom


You can run Drupal tests using either Selenium or headless Chrome. Acquia Pipelines doesn’t support Selenium (due to Java not being installed). Therefore, you must run the tests using headless Chrome in Pipelines.

Drupal’s script

You can customize the tests:drupal:run command by modifying your BLT configuration for the tests:run-tests key.

Each row under the tests:drupal-tests key should contain a combination of the following properties. For a description of each property, see the Drupal documentation.

  • all

  • browser

  • clean

  • color

  • concurrency

  • dburl

  • die-on-fail

  • directory

  • keep-results-table

  • keep-results

  • repeat

  • sqlite

  • suppress-deprecations

  • tests (array)

  • types (array, takes precedence over type)

  • type

  • url

      - # Run the PHPUnit-Unit, PHPUnit-Kernel, and PHPUnit-Functional test types for the action module.
        color: true
        concurrency: 2
          - 'PHPUnit-Unit'
          - 'PHPUnit-Kernel'
          - 'PHPUnit-Functional'
          - 'action'
        sqlite: '${tests.drupal.sqlite}'
        url: '${tests.drupal.simpletest-base-url}'
      - # Run the PHPUnit-FunctionalJavascript test type for the action module.
        color: true
        concurrency: 1
          - 'PHPUnit-FunctionalJavascript'
          - 'action'
        sqlite: '${tests.drupal.sqlite}'
        url: '${tests.drupal.simpletest-base-url}'
      - # Run the Simpletest test type for the user module.
        color: true
        concurrency: 1
          - 'Simpletest'
          - 'user'
        sqlite: '${tests.drupal.sqlite}'
        url: '${tests.drupal.simpletest-base-url}'

Front-end testing

BLT supports a frontend-test target that can be used to execute several testing frameworks. Examples include Jest, Jasmine, Mocha, and Chai.


You can customize the configuration values for the frontend-test key to enable this capability of BLT.