Behat

Note: This page is a work-in-progress. Feedback and suggested improvements are welcome. Please join the discussion on moodle.org or use the page comments.

Introduction

This page describes how we describe Moodle functionalities and how we automatically test all of this Moodle's functionalities.

Behat is a behavioural driven development (BDD) tool written in PHP, it can parse a human-readable list of sentences (called steps) and execute actions in a browser using Selenium or other tools to simulate users interactions.

(This is not in standard Moodle yet: to play a bit with it now clone https://github.com/moodlehq/moodle-behat-features and follow the installation and usage instructions.)

How it works

Behat parses and executes features files which describes Moodle features (for example Post in a forum), each feature file is composed by many scenarios (for example Add a post to a discussion or Create a new discussion), and finally each scenario is composed by steps (for example  I press "Post to Forum" or I should see "My post title"). When the feature file is executed, every step internally is translated into an PHP method and is executed.

This features are executed nightly in the HQ servers with all the supported databases (MySQL, PostgreSQL, MSSQL and Oracle) and with different browsers (Firefox, Internet Explorer, Safari and Chrome) to avoid regressions and test new functionalities.

Examples

• There is a closed list of steps to use in the features, a feature written with the basic (or low-level) steps looks like this:

 @auth
 Feature: Login
   In order to login
   As a moodle user
   I need to be able to validate the username and password against moodle
   
   Scenario: Login as an existing user
     Given I am on "login/index.php"
     When I fill in "username" with "admin"
     And I fill in "password" with "moodle"
     And I press "loginbtn"
     Then I should see "Moodle 101: Course Name"
   
   Scenario: Login as an unexisting user
     Given I am on "login/index.php"
     When I fill in "username" with "admin"
     And I fill in "password" with "moodle"
     And I press "loginbtn"
     Then I should see "Moodle 101: Course Name"

Note that The 3 sentences below Feature: Login are only information about what we want to test.

These are simple scenarios, but most of Moodle functionalities would require a huge list of this steps to test a scenario, imagine a Add a post to a discussion scenario; you need to login, create a course, create a user and enrol it in the course... Most of this steps is not what we intend to test in a Post in a forum feature, Moodle provides extra steps to quickly set up the context required to test a Moodle feature, for example:

 @mod_forum
 Feature: Post in a forum
   In order to add contents to a forum
   As a moodle user
   I need to be able to enter the contents and verify they are correctly shown
   
   Background:
     Given the following "courses" exists
       | fullname | shortname |
       | Course 1 | C1        |
     And the following "users" exists
       | username | firstname | lastname | email        |
       | student1 | First     | Student  | stu1@asd.com |
     And the following "enrolments" exists
       | username | courseshortname | enrolmenttype |
       | student1 | C1              | manual        |
   
   Scenario: Create a forum
     Given I loggin as an "admin"
     And I go to "Course 1" course
     And I add a "forum" to section "1"
     And I fill the form with
       | Forum name        | ForumTest1                     |
       | Forum description | Test description               |
       | Forum type        | Standard forum for general use |
       | Any other field   | Value                          |
     When I press "Save and display"
     Then I should see "Test1"
     And I should see "Add a new discussion topic"
   
   Scenario: Add a post to a discussion
     Given I run "Create a forum" scenario
     And I go to "Course 1" course
     And I follow "ForumTest1"
     When I press "Add a new discussion topic"
     And I fill the form with
       | Subject | test subject |
       | Message | message body |
     And I press "Post to forum"
     Then I should see "test subject"

Note that:

• Background is executed before each scenario execution
• Each scenario is executed in an isolated testing environment, so what you set up in an scenario (like the ForumTest1 forum in the example above) is cleaned up after the scenario execution
• The prefixes "Given", "When" and "Then" are only informative and they as used to define the context (Given), specify the action (When) and check the results (Then).

Links

Technical info: https://docs.moodle.org/dev/Behat_integration