Continuous Integration and Drupal

CONTINUOUS INTEGRATIONAutomatically Install, Test, and Deploy Your Drupal Site

Wednesday, December 16, 2009

Testing and Drupal

The focus of Drupal 7 has largely been on automated testing and Drupal adopted SimpleTest as its test framework of choice.

Major Drupal 6 modules are starting to get unit tests, but their correctness varies.

Regardless, it’s still easy to write your own unit tests.


SimpleTest

SimpleTest is a testing framework that has been adopted for use in Drupal core and contrib.

Drupal 7 core is automatically tested using the PIFR module and testing slaves.

We’ll talk later about getting SimpleTests running automatically as part of our Hudson continuous integration framework.


Running Tests

SimpleTest is a contributed module for Drupal 6. It is in Drupal 7 core, and it also happens to be part of the Pressflow distribution’s core set of modules.

To run tests, the SimpleTest module must be enabled. (Our install profile turns it on by default.) Then you can head to /admin/build/testing to see all the available tests.


The SimpleTest Interface

Each test shown in the SimpleTest administrative interface is an instance of the DrupalWebTestCase class. Each of these tests may contain multiple assertions.


Running Tests

For each assertion in a test, SimpleTest will log whether each passed or failed, along with any PHP exceptions that happen along the way.


Testing Workflow

Ideally, SimpleTests should all be run prior to a commit so that we’re not relying on Hudson to find errors in unit tests.

As of right now, quite a few contributed modules have test failures.


Writing SimpleTests

SimpleTest looks for .test files. They should be placed inside a tests folder in your module’s folder. (The modules for Drupal 7’s tests, and the backported block tests for Pressflow are located in the <htdocs>/modules/simpletest/tests.)

Each .test file may contain one or more classes that extend DrupalWebTestCase.


DrupalWebTestCase

The DrupalWebTestCase (hereafter DWTC) class defines a number of extra helper methods besides the ones provided by SimpleTest and also defines a Drupal-specific default setup and teardown behavior.

You can find the definition for this class at drupal_web_test_case.php inside the simpletest folder.


Your Test Classes

Each class that inherits from DWTC should provide an implementation of the DrupalWebTestCase::getInfo() method:

function getInfo() { return array( 'name' => t('RSS and XML formatting tests'), 'description' => t('Tests for the format_rss_item() and format_xml_elements() functions.'), 'group' => t('System'), ); }

This information shows up on the SimpleTest admin screen.


Your Tests

In addition to getInfo(), you must create a least one testing method. SimpleTest will run any public methods whose names begin with “test”.


Behind the Scenes

So how does SimpleTest work without disturbing your local database? The real magic happens in the DrupalWebTestCase::setUp() method. That method creates a new random numerical prefix and then uses Drupal’s database prefixing feature to install a new, empty copy of Drupal with the default install profile using the random database prefix.

It also creates a temporary files directory (also prefixed with the random number) in the current files directory.


Behind The Scenes, Cont’d

Although it doesn’t show it as a parameter, ::setUp() will also take a variable number of extra arguments as modules that should be enabled in addition to those that come with the default profile.

Since block.module is enabled in the default install profile, for example, BlockTestCase doesn’t have to call setUp() with any extra arguments. However, CCK’s tests need to look in the database, and so they need at least the content and text CCK modules, and the schema module to examine DB schema.


Looking At Tests

Here’s the BlockTestCase from block.test:

class BlockTestCase extends DrupalWebTestCase { public static function getInfo() { return array( 'name' => t('Block functionality'), 'description' => t('Add, edit and delete custom block. Configure and move a module-defined block.'), 'group' => t('Block'), ); }


Looking At TestsHere’s the BlockTestCase from block.test:

/** * Implementation of setUp(). */ function setUp() { parent::setUp(); // Create and login user $admin_user = $this->drupalCreateUser(array('administer blocks')); $this->drupalLogin($admin_user); }


Looking At TestsCompare that to the CCK ContentCrudTestCase, which is a base class that other CCK tests inherit from. Note how the setUp() method is set to enable the three modules the test will need.

class ContentCrudTestCase extends DrupalWebTestCase { function setUp() { $args = func_get_args(); $modules = array_merge(array('content', 'schema', 'text'), $args); call_user_func_array(array('parent','setUp'), $modules); module_load_include('inc', 'content', 'includes/content.crud');


Basic Assertions

The main assertions that are built into the UnitTestCase class (from which DrupalWebTestCase inherits) are documented at http://simpletest.org/api/SimpleTest/UnitTester/UnitTestCase.html .


http://simpletest.org/api/SimpleTest/UnitTester/UnitTestCase.html




DrupalWebTestCase

DrupalWebTestCase inherits from the SimpleTest library’s WebTestCase class, but also adds extra capabilities for accessing Drupal pages by URL, setting the logged in user, submitting forms with ::drupalPost() and more.

You can read about these functions at http://drupal.org/node/265762 .


http://drupal.org/node/265762




Test Types

Sometimes you will want to create purely functional tests, as in one I wrote for D7 HEAD to test format_rss_item. This just tests the validity of a regular expression for several common possible XML tags.

function testElementNameRegex() { $regex = '/^[\w:][\w\-:]*$/'; $this->assertEqual(preg_match($regex, 'i<3badlyformattedtags'), 0, t('XML Element Regex is valid')); $this->assertEqual(preg_match($regex, 'georss:point'), 1, t('XML Element Regex is valid')); $this->assertEqual(preg_match($regex, ' not:valid'), 0, t('XML Element Regex is valid')); $this->assertEqual(preg_match($regex, '-not-so-valid'), 0, t('XML Element Regex is valid')); }


Test TypesMost of your tests will involve using APIs, such as this test that tests the format_rss_item() call to make sure it escapes XSS.

function testXSS() { $sanitized_title = check_plain($this->getRSSTitle()); $sanitized_link = check_url($this->getRSSLink()); $sanitized_description = check_plain($this->getRSSDescription()); $output = format_rss_item($this->getRSSTitle(), $this->getRSSLink(), $this->getRSSDescription(), array()); $simplexml_result = simplexml_load_string($output);


Test TypesMost of your tests will involve using APIs, such as this test that tests the format_rss_item() call to make sure it escapes XSS.

$this->assertTrue($simplexml_result !== FALSE, t('SimpleXML could properly parse the output')); $this->assertTrue(strpos($output, $sanitized_title) != FALSE, t('XSS attack %title was filtered', array('%title' => $this->getRSSTitle()))); $this->assertTrue(strpos($output, $sanitized_link) != FALSE, t('Potentially dangerous URL %link was filtered to %sanitized_link', array('%link' => $this->getRSSLink(), '%sanitized_link' => $sanitized_link)));


Test-Driven Development

A major focus of many agile development practices are Test-Driven (or Behavior-Driven) Development, whereby unit tests are written first to satisfy requirements, and can be continually tested as the project progresses.

Another common thread in doing TDD is to bring tests into bug fixes. In many open-source projects, such as jQuery, people ask for a test case to demonstrate a bug, and then a new test can be written so that the regression never happens again.


Running Tests

Can take a long time, especially if your install profile grows.

Maybe we can enlist someone else to help out with them.


Enter Hudson


Installing Hudson

Debian-based packages are available for Ubuntu

http://hudson-ci.org/debian/

You can also run Hudson on Tomcat (beside a SOLR install, for example.)

Hudson on Ubuntu installs your files at /var/lib/hudson/jobs/[your job name]/workspace/[top-level SCM package]




Getting Hudson Working

Set up source control

Set up a build step that installs Drupal

Set up a build step that runs SimpleTests via the shell script

Set up JUnit reporting

Profit?


Setting Up Source Control

Put your SVN (or CVS or Mercurial, etc.) information into Hudson and save either credentials and/or a public/private keypair

Set it up to automatically poll your repository for changes if you want automatic builds


Automatically Installing

Make a vhost and a hosts entry for your Hudson checkout

You’ll then want to make a shell script that:

Runs drush provision to install your site

Make sure your install profile installs SimpleTest!


Automatically Installing

A sample script:#!/bin/bashSITE_PATH=/var/lib/hudson/jobs/ProvisionTest/workspace/trunk/htdocscd $SITE_PATH/bin/drush --root=$SITE_PATH --master_db_host=localhost --master_db_user=root --db_type=mysql --db_host=localhost --config_path=/etc/apache2/drush-conf --restart_cmd=echo --uri=http://drushtest --script_user=hudson --profile=provision provision install drushtest


http://drushtest

http://drushtest

Running SimpleTests

Your install profile must install SimpleTest so that you can use the run-tests.sh script to run a number of tests.

ComputerMinds.co.uk started a SimpleTest patch to output test results in the JUnit XML format - this patch will be in Pressflow soon and is active on d.o: http://drupal.org/node/602332

Once you’re running this patch, your Hudson runs will keep track of the number of test passes and fails.




Running SimpleTests

The other half of the same script, to handle automatically running SimpleTests:

rm -rf scripts/tests/*.xml/usr/bin/php scripts/run-tests.sh --url http://drushtest --xml scripts/tests Provision


http://drushtest

http://drushtest

Hudson Results

Build failure: when Drupal could not be installed, drush will return with an error, and Hudson will notify you that the build has failed.

Common causes of this could be parse errors, modules that aren’t in source control but are referred to in the install profile, and so on.

Unstable: the installation succeeded, but one or more unit tests did not complete successfully.


Hudson Results

Success: Your installation succeeded and all unit tests passed!


Unit Testing Recipes

Test your install profile!

http://gist.github.com/249754

This code will let you make a unit test that installs your full install profile (in this case, called “provision”) and can then run tests against the fully-installed environment.




GotchasDrush Provision isn’t _really_ meant to install one site many times. If your site’s URL is more than 14 characters, it will fail after the 10th install, since it makes a new database each time.

All those databases will eventually slow your MySQL server down, so you manually have to remove them.

Make sure that you install Provision for both the Hudson / Tomcat user and the main web user.

Make sure you install curl, php-cli and php-curl so that SimpleTests can run from the command line.


Date post:	25-Dec-2014
Category:	Technology
Upload:	steven-merrill
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