Moodle behat testing

Moodle Behat Testing

Overview

Behat drives a real browser against a dedicated Moodle test site. Features live in <plugin>/tests/behat/*.feature. Custom steps go in tests/behat/behat_<component>.php extending behat_base. Moodle provides hundreds of built-in steps (login, course creation, navigation).

When to Use

• Writing end-to-end / acceptance tests
• Testing JavaScript-driven UI (drag-drop, modals, AJAX)
• Reproducing bugs that need full request cycle + cookies + session
• Adding scenarios to a plugin's regression suite

Skip when: writing unit tests for business logic — use moodle-phpunit-testing.

First-time setup

# config.php additions:
$CFG->behat_wwwroot   = 'http://localhost:8000';
$CFG->behat_dataroot  = '/var/moodledata_behat';
$CFG->behat_prefix    = 'beh_';

# Initialize test site:
php admin/tool/behat/cli/init.php

# Install + start a Selenium-compatible driver (one of):
docker run -d -p 4444:4444 selenium/standalone-chrome:latest
# or chromedriver, geckodriver

# Run:
vendor/bin/behat --config /var/moodledata_behat/behat/behat.yml \
  --tags @local_example

Feature file skeleton

@local_example @javascript
Feature: Mark attendance
  In order to track presence
  As a teacher
  I need to mark students present

  Background:
    Given the following "courses" exist:
      | fullname | shortname |
      | Maths    | M101      |
    And the following "users" exist:
      | username | firstname | lastname |
      | teacher1 | Tina      | Teach    |
      | student1 | Sam       | Student  |
    And the following "course enrolments" exist:
      | user     | course | role           |
      | teacher1 | M101   | editingteacher |
      | student1 | M101   | student        |

  Scenario: Teacher marks a student present
    Given I log in as "teacher1"
    And I am on "Maths" course homepage
    When I follow "Attendance"
    And I click on "Mark present" "button" in the "Sam Student" "table_row"
    Then I should see "1 present" in the "Today" "fieldset"

Tags:

• @<component> — required for --tags filtering
• @javascript — uses real browser; without it, runs headless (Goutte) — fast but no JS
• @_file_upload, @_switch_window, @_alert — capability tags so runner can skip on incompatible drivers

Background data generators

Moodle exposes generators as Behat steps via behat_data_generators:

Given the following "local_example > items" exist:
  | course | name        | userid    |
  | M101   | First item  | student1  |

To enable, declare in tests/generator/lib.php AND register in tests/behat/behat_local_example.php:

public function get_creatable_entities(): array {
    return [
        'items' => [
            'singular' => 'item',
            'datagenerator' => 'item',
            'required' => ['name'],
            'switchids' => ['course' => 'courseid', 'user' => 'userid'],
        ],
    ];
}

Generator method:

// in local_example_generator
public function create_item(array $record): \stdClass {
    // same as PHPUnit generator
}

Custom step definitions

tests/behat/behat_local_example.php:

<?php
require_once(__DIR__ . '/../../../../lib/behat/behat_base.php');

use Behat\Mink\Exception\ExpectationException;

class behat_local_example extends behat_base {

    /**
     * @Given /^there are (\d+) attendance items$/
     */
    public function there_are_n_items(int $count): void {
        $gen = \testing_util::get_data_generator()
            ->get_plugin_generator('local_example');
        for ($i = 0; $i < $count; $i++) {
            $gen->create_item();
        }
    }

    /**
     * @Then /^the attendance count should be "(\d+)"$/
     */
    public function attendance_count_should_be(int $expected): void {
        global $DB;
        $actual = $DB->count_records('local_example_items');
        if ($actual !== $expected) {
            throw new ExpectationException(
                "Expected $expected, got $actual",
                $this->getSession()
            );
        }
    }
}

Class name must match behat_<component>. After adding/changing steps:

php admin/tool/behat/cli/init.php    # re-scan

Running

# All Behat for plugin
vendor/bin/behat --config $CFG->behat_dataroot/behat/behat.yml --tags @local_example

# Single feature
vendor/bin/behat --config ... tests/behat/mark_attendance.feature

# Single scenario (line number)
vendor/bin/behat --config ... tests/behat/mark_attendance.feature:23

# Parallel (4 runners)
php admin/tool/behat/cli/init.php --parallel=4
vendor/bin/moodle_behat_parallel_run --tags @local_example

Selectors (Mink)

Type	Example
link	I follow "Settings"
button	I press "Save changes"
field	I set the field "Name" to "X"
select	I set the field "Role" to "Manager"
checkbox	I check "Visible"
table_row	... in the "Alice" "table_row"
fieldset	... in the "General" "fieldset"
dialogue	... in the "Confirm" "dialogue"
css_element	I click on ".foo .bar" "css_element"
xpath_element	I click on "//button[@data-x='y']" "xpath_element"

Useful built-in steps

And I am on the "Course 1" "course" page logged in as "teacher1"
And I navigate to "Users > Enrolment methods" in current course administration
And I should see "X" in the "block_settings" "block"
And I wait until the page is ready
And I wait "2" seconds                # avoid; prefer wait-until
And I run the scheduled task "\local_example\task\cleanup"
And I run all adhoc tasks
And the following config values are set as admin:
  | config        | value | plugin        |
  | enabled       | 1     | local_example |

Common Mistakes

Mistake	Fix
Adding step but not running behat/cli/init.php	Re-init after every PHP step change
Missing @javascript for AJAX UI	Tag scenario @javascript and run with browser driver
Hard-coded sleeps I wait 5 seconds	Use I wait until ... exists/disappears
Class name mismatch	Must be behat_<component>
Not switching to dialogue context	Add in the "..." "dialogue" selector
Forgetting capability tags (@_file_upload)	Add so runner can skip on incompatible browsers
Editing behat.yml directly	Regenerated by init.php — config in config.php instead

Debugging

# Save HTML+screenshot on failure
$CFG->behat_faildump_path = '/tmp/behat-fails';

# Run a single scenario in foreground browser
vendor/bin/behat --config ... --tags @mytag --stop-on-failure -v

# Pause for inspection
And I should see "this will fail"     # forces a wait you can attach to

CI snippet

- name: Behat
  run: |
    php admin/tool/behat/cli/init.php
    vendor/bin/behat --config $MOODLE_DATA/behat/behat.yml \
      --tags @local_example --format=progress

References

• Behat in Moodle: https://moodledev.io/general/development/tools/behat
• Writing tests: https://moodledev.io/general/development/tools/behat/writing
• Step reference: https://moodledev.io/general/development/tools/behat/writing#step-definitions
• Data generators: https://moodledev.io/docs/apis/subsystems/testing/generators#behat