talks/tdd-test-driven-drupal/2017-03-04-drupalcamp-london/slides.md

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Test Driven Drupal Development with SimpleTest and PHPUnit

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opdavies

• Web Developer and Linux System Administrator
• Drupal core contributor, mentor, contrib module maintainer
• Senior Drupal Developer, Appnovation

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Why Test?

• Write better code
• Write less code
• Piece of mind
• Ensure consistency
• Drupal core requirement - https://www.drupal.org/core/gates#testing

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Why Not Test?

No time/budget to write tests.

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Core Testing Gate

New features should be accompanied by automated tests. If the feature does not have an implementation, provide a test implementation. Bug fixes should be accompanied by changes to a test (either modifying an existing test case or adding a new one) that demonstrate the bug. -- https://www.drupal.org/core/gates#testing

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Testing in Drupal

SimpleTest

• Based on http://www.SimpleTest.org
• In D7 core
• *.test files
• All test classes in one file

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Testing in Drupal

PHPUnit

• Used in other PHP projects (e.g. Symfony, Laravel)
• In D8 core, but not default
• *.php files
• One test class per file

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The PHPUnit Initiative

• https://www.drupal.org/node/2807237
• D8 core tests to change to PHPUnit
• Deprecate SimpleTest, remove in D9
• "A big chunk of old tests" converted on Feb 21st

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The PHPUnit Initiative

As part of the PHPUnit initiative a considerable part of Simpletests will be converted to PHPUnit based browser tests on February 21st 2017. A backwards compatibility layer has been implemented so that many Simpletests can be converted by just using the new BrowserTestBase base class and moving the test file. There is also a script to automatically convert test files in the conversion issue. Developers are encouraged to use BrowserTestBase instead of Simpletest as of Drupal 8.3.0, but both test systems are fully supported during the Drupal 8 release cycle. The timeline for the deprecation of Simpletest's WebTestBase is under discussion. -- https://groups.drupal.org/node/516229

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Types of Tests

Unit Tests

• Tests PHP logic
• No database interaction
• Fast to run

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Types of Tests

Web Tests

• Tests functionality
• Interacts with database
• Slower to run

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Writing Testable Code

• Single responsibility principle
• DRY
• Dependency Injection
• Interfaces

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Test Driven Development (TDD)

• Write a test, see it fail
• Write code until test passes
• Repeat
• Refactor when tests are green

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Writing Tests

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# example.info

name = Example
core = 7.x
files[] = example.test

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// example.test

class ExampleTestCase extends DrupalWebTestCase {

  public static function getInfo() {
    return array(
      'name' => 'Example tests',
      'description' => 'Web tests for the example module.',
      'group' => 'Example',
    );
  }

}

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class ExampleTestCase extends DrupalWebTestCase {

  ...

  public function testSomething {
    $this->assertTrue(TRUE);
  }

}

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Creating the World

public function setUp() {
  // Enable any other required modules.
  parent::setUp(['foo', 'bar']);

  // Anything else we need to do.
}

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Creating the World

$this->drupalCreateUser();

$this->drupalLogin();

$this->drupalCreateNode();

$this->drupalLogout();

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Assertions

• assertTrue
• assertFalse
• assertNull
• assertNotNull
• assertEqual

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Assertions

• assertRaw
• assertResponse
• assertField
• assertFieldById
• assertTitle

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Running Tests

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Running SimpleTest From The Command Line

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# Drupal 7
$ php scripts/run-tests.sh

# Drupal 8
$ php core/scripts/run-tests.sh

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Running SimpleTest From The Command Line

--color

--verbose

--all

--module

--class

--file

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Running PHPUnit From The Command Line

$ phpunit

$ phpunit [directory]

$ phpunit --filter [method]

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Example: Collection Class

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Collection Class

• http://dgo.to/collection_class
• Adds a Collection class, based on Laravel’s
• Provides helper methods for array methods

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$collection = collect([1, 2, 3, 4, 5]);

// Returns all items.
$collection->all();

// Counts the number of items.
$collection->count();

// Returns the array keys.
$collection->keys();

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namespace Drupal\collection_class;

class Collection implements \Countable, \IteratorAggregate {
  private $items;

  public function __construct($items = array()) {
    $this->items = is_array($items) ? $items
      : $this->getArrayableItems($items);
  }

  public function __toString() {
    return $this->toJson();
  }

  ...

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public function all() {
  return $this->items;
}

public function count() {
  return count($this->items);
}


public function isEmpty() {
  return empty($this->items);
}

public function first() {
  return array_shift($this->items);
}

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Testing

public function setUp() {
  $this->firstCollection = collect(['foo', 'bar', 'baz']);

  $this->secondCollection = collect([
      array('title' => 'Foo', 'status' => 1),
      array('title' => 'Bar', 'status' => 0),
      array('title' => 'Baz', 'status' => 1)
  ]);

  parent::setUp();
}

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Testing

public function testCollectFunction() {
  $this->assertEqual(
    get_class($this->firstCollection),
    'Drupal\collection_class\Collection'
  );
}

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Testing

public function testAll() {
  $this->assertEqual(
    array('foo', 'bar', 'baz'),
    $this->firstCollection->all()
  );
}

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Testing

public function testCount() {
  $this->assertEqual(
    3,
    $this->firstCollection->count()
  );
}

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Testing

public function testMerge() {
  $first = collect(array('a', 'b', 'c'));
  $second = collect(array('d', 'e', 'f'));

  $this->assertEqual(
    array('a', 'b', 'c', 'd', 'e', 'f'),
    $first->merge($second)->all()
  );
}

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Example: Toggle Optional Fields

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Toggle Optional Fields

• http://dgo.to/toggle_optional_fields
• Adds a button to toggle optional fields on node forms using form alters
• Possible to override using an custom alter hook
• Uses unit and web tests

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Example

// Looping through available form elements...

// Only affect fields.
if (!toggle_optional_fields_element_is_field($element_name)) {
  return;
}

$element = &$form[$element_name];

if (isset($overridden_fields[$element_name])) {
  return $element['#access'] = $overridden_fields[$element_name];
}

// If the field is not required, disallow access to hide it.
if (isset($element[LANGUAGE_NONE][0]['#required'])) {
  return $element['#access'] = !empty($element[LANGUAGE_NONE][0]['#required']);
}

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What to Test?

• Functional: Are the correct fields shown and hidden?
• Unit: Is the field name check returning correct results?

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Unit Tests

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// Returns TRUE or FALSE to indicate if this is a field.

function toggle_optional_fields_element_is_field($name) {
  if (in_array($name, array('body', 'language'))) {
    return TRUE;
  }

  return substr($name, 0, 6) == 'field_';
}

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Unit Tests

$this->assertTrue(
  toggle_optional_fields_element_is_field('field_tags')
);

$this->assertTrue(
  toggle_optional_fields_element_is_field('body')
);

$this->assertFalse(
  toggle_optional_fields_element_is_field('title')
);

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Web Tests

public function setUp() {
  parent::setUp();

  $this->drupalLogin(
    $this->drupalCreateUser(array(
      'create article content',
      'create page content'
    ));
  );

  // Enable toggling on article node forms.
  variable_set('toggle_optional_fields_node_types', array('article'));

  $this->refreshVariables();
}

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Custom Assertions

private function assertTagsFieldNotHidden() {
  $this->assertFieldByName(
    'field_tags[und]',
    NULL,
    t('Tags field visible.')
  );
}

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Testing Hidden Fields

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public function testFieldsHiddenByDefault() {
  variable_set('toggle_optional_fields_hide_by_default', TRUE);

  $this->refreshVariables();

  $this->drupalGet('node/add/article');

  $this->assertShowOptionalFieldsButtonFound();
  $this->assertHideOptionalFieldsButtonNotFound();
  $this->assertTagsFieldHidden();

  ...

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Testing Hidden Fields

  ...

  $this->drupalPost(
    'node/add/article',
    array(),
    t('Show optional fields')
  );

  $this->assertHideOptionalFieldsButtonFound();
  $this->assertShowOptionalFieldsButtonNotFound();
  $this->assertTagsFieldNotHidden();
}

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Take Aways

• Testing can produce better quality code
• Writing tests is an investment
• OK to start small, introduce tests gradually

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Questions?