Part 2: Automated Drupal testing with Behat, Selenium, and Headless Firefox

Verify Prerequisites

I assume you have the following already installed:

• Ubuntu 14.04
• Java RTE
• Composer
• PHP 5.4+
• PHP's Curl module

Installation

Have Composer Install Dependencies

We'll let Composer handle the majority of the work. We'll need to tell Composer what dependencies our project requires.

Create composer.json

Create a composer.json file that contains all our required packages by pasting in the following:

{
  "require": {
    "behat/behat": "~3.0",
    "behat/mink-goutte-driver": "~1.2.0",
    "behat/mink-extension": "~2.1",
    "behat/mink-selenium2-driver": "~1.3",
    "drupal/drupal-extension": "~3.1"
  }
}

Composer Install

Have Composer install our needed packages. From the same directory the composer.json file is in, run:

composer install

PHP Fatal error:  Uncaught exception 'ErrorException' with message 'proc_open(): fork failed - Cannot allocate memory'

Setup Behat

Behat will handle all the actual test cases. We'll configure some path settings and have Behat initialize our directory structure.

Create behat.yml

Create a new file called behat.yml and paste in the following:

default:
  autoload:
    '': %paths.base%/features/bootstrap
  suites:
    default:
      paths:
        - %paths.base%/features
      contexts:
        - FeatureContext
        - Drupal\DrupalExtension\Context\DrupalContext
        - Drupal\DrupalExtension\Context\MinkContext
        - Drupal\DrupalExtension\Context\MessageContext
  extensions:
    Behat\MinkExtension:
      goutte: ~
      selenium2: ~
      base_url: https://drupal.org/
    Drupal\DrupalExtension:
      blackbox: ~
      region_map:
        header_nav: ".wx-header-tools"

We're using Behat 3.x so the autoload and path settings look a little different from the old 2.5 version.

Notice the use of blackbox. It comes with the DrupalExtension; it allows us to find elements within a "region" for situations where the target element doesn't have a unique selector. See Blackbox docs for more information.

Initialize Behat Config

Now that we have our behat.yml file configured, let's have Behat initialize a working directory tree.

./vendor/bin/behat --init

You should get some green outputs about where to put features and context classes.

Install Firefox

Nothing special here. Just use apt-get to install the current stable release of Firefox.

sudo apt-get install firefox

Install & Configure Xvfb

We'll use Xvfb to create a dummy display for Firefox to run in.

Install Xvfb

sudo apt-get -y install xvfb gtk2-engines-pixbuf
sudo apt-get -y install xfonts-cyrillic xfonts-100dpi xfonts-75dpi xfonts-base xfonts-scalable

Configure Xvfb Display

We need to configure a display number kind of high to avoid collision with existing displays.

sudo Xvfb :10 -ac -screen 0 1024x768x8 &

You may get a warning about missing font paths; this is okay, just ctrl+c. Verify Xvfb is running by running:

ps aux | grep -P "^root.*Xvfb"

You should get one or two lines back that look like:

root     11345  0.0  2.7 136480 13724 pts/0    S    00:24   0:00 Xvfb :10 -ac

Set Environment Display Variable

We need to update the DISPLAY environment variable so Firefox will know what to attach to.

export DISPLAY=:10

Download & Configure Selenium

Download Selenium Standalone

Download the latest jar file.

curl -J -O -L http://selenium-release.storage.googleapis.com/2.53/selenium-server-standalone-2.53.0.jar

We'll make a symbolic link to a filename without Selenium's version number.

  ln -s ./selenium-server-standalone-2.53.0.jar ./selenium-server-standalone.jar

Selenium - Hub (aka Server)

Selenium can be configured to run as a hub, a node, or standalone. For this tutorial, we'll configure the hub first, then add a node.

Create a script called start-selenium-hub.sh that will start our Seleniun Hub.
Paste the following code in this new file:

#!/bin/bash
 
java -jar ./selenium-server-standalone.jar -role hub -host 0.0.0.0 > ./selenium-hub.log 2>&1 &

Give the script executable permissions and run it:

  chmod u+x ./start-selenium-hub.sh
  ./start-selenium-hub.sh

Selenium - Node

Create a script called start-selenium-node.sh that will start our Selenium node.
Paste the following code in this new file:

#!/bin/bash
 
if [ ! -f /tmp/.X5-lock ]; then
  /usr/bin/Xvfb :10 -ac -screen 0 1024x768x8 &
fi
 
export DISPLAY=:10 # firefox needs this to know where to find a display to run on
 
java -jar ./selenium-server-standalone.jar -role node -hub http://127.0.0.1:4444/grid/register/ > ./selenium-node.log 2> ./selenium-node.err &

Give the script executable permissions and run it:

  chmod u+x ./start-selenium-node.sh
  ./start-selenium-node.sh

Behat Test Scripts

We're almost ready to run our test scripts!

Write our first test script!

We're going to do a test search on drupal.org for our test.
When we ran /vendor/bin/behat --init earlier, a file features/test.feature was created. This is where we'll store our test cases.

Add the following to the features/test.feature file:

Feature: Drupal.org search
  Searching for behat from drupal.org's search box.
 
  @javascript
  Scenario: Searching for "behat"
    Given I go to "https://www.drupal.org"
    When I search for "behat"
    Then I should see "Behat Drupal Extension"

Tell Behat how to search

We'll be testing Drupal.org's search box. For this, we need to write a custom step definition for: "I search for".

Earlier when we ran /vendor/bin/behat --init, it generated a file: features/bootstrap/FeatureContext.php. In this file, add the follow snippet:

/**
 * @When /^I search for "([^"]*)"$/
 */
public function iSearchFor($search_term)
{
  $page = $this->getSession()->getPage();
  $page->fillField('Search', $search_term);
  $page->pressButton('Search');
}

Run our tests

Make sure you are currently in the directory that contains the behat.yml. Run the following command:

vendor/bin/behat

You should get an output similar to:

Feature: Drupal.org search
  Searching for behat from drupal.org's search box.
 
  @javascript
  Scenario: Searching for "behat"              # features/test.feature:5
    Given I go to "https://www.drupal.org"     # Drupal\DrupalExtension\Context\MinkContext::visit()
    When I search for "behat"                  # FeatureContext::iSearchFor()
    Then I should see "Behat Drupal Extension" # Drupal\DrupalExtension\Context\MinkContext::assertPageContainsText()
 
1 scenario (1 passed)
3 steps (3 passed)
0m9.66s (14.59Mb)

      Unable to connect to host 127.0.0.1 on port 7055 after 45000 ms.