Build/Test Tools: Fix test forward-compatibility layer.

In [51845], the test wrapper methods were not being called due to the names not being recognized as supported PHPUnit "hook" names for fixtures.

This commit:
- Fixes the problem by adding extra camelCase wrappers to the `WP_UnitTestCase` to call the methods in the right order.
- Adds wrappers for the `assertPreConditions()` and `assertPostConditions()` fixture methods to make the backport feature complete for the fixture wrappers.

Test wrapper methods call fix:

By adding method overloads for the PHPUnit native camelCase fixture methods and letting those call the (camelCase) parent method first and only calling the snake_case fixture methods after, the snake_case methods can be supported and the typical run order safeguarded.

As not all test classes will have declared snake_case fixture methods, the snake_case fixture methods are also declared in the `WP_UnitTestCase`. Why? This prevents having to wrap these method calls in `method_exists()` conditions checking for the existence of the snake_case methods in an unknown Test child class. And with the normal inheritance rules in combination with calling the method using `static`, the right method will be called anyway without fatal "calling undeclared method" errors.

Note: While it will be rare, there ''may'' be cases where a test class does not adhere to the normal execution order for fixtures, i.e. for the setup methods, parent first, own code second; and for the teardown methods, own code first, parent second. For example a test class which has "some code - `parent::setUp()` call - some more code" in their `setUp()` method. In those (rare) cases, the execution order of the code will now be changed, which may have side-effects. This rare case will be identified in the dev note.

Follow-up to [51845], [51848].

Props bjorsch, swissspidy, jrf, hellofromTonya.
See #53911.

git-svn-id: https://develop.svn.wordpress.org/branches/5.3@51866 602fd350-edb4-49c9-b593-d223f7449a82

Author: hellofromtonya

tests/phpunit/includes/phpunit7/testcase.php

@@ -46,30 +46,80 @@ class WP_UnitTestCase extends WP_UnitTestCase_Base {
 	use ExpectPHPException;
 
 	/**
-	 * Wrapper method for the `setUpBeforeClass()` method for forward-compatibility with WP 5.9.
+	 * Wrapper method for the `set_up_before_class()` method for forward-compatibility with WP 5.9.
 	 */
-	public static function set_up_before_class() {
-		static::setUpBeforeClass();
+	public static function setUpBeforeClass() {
+		parent::setUpBeforeClass();
+		static::set_up_before_class();
 	}
 
 	/**
-	 * Wrapper method for the `tearDownAfterClass()` method for forward-compatibility with WP 5.9.
+	 * Wrapper method for the `tear_down_after_class()` method for forward-compatibility with WP 5.9.
 	 */
-	public static function tear_down_after_class() {
-		static::tearDownAfterClass();
+	public static function tearDownAfterClass() {
+		static::tear_down_after_class();
+		parent::tearDownAfterClass();
 	}
 
 	/**
-	 * Wrapper method for the `setUp()` method for forward-compatibility with WP 5.9.
+	 * Wrapper method for the `set_up()` method for forward-compatibility with WP 5.9.
 	 */
-	public function set_up() {
-		static::setUp();
+	public function setUp() {
+		parent::setUp();
+		$this->set_up();
 	}
 
 	/**
-	 * Wrapper method for the `tearDown()` method for forward-compatibility with WP 5.9.
+	 * Wrapper method for the `tear_down()` method for forward-compatibility with WP 5.9.
 	 */
-	public function tear_down() {
-		static::tearDown();
+	public function tearDown() {
+		$this->tear_down();
+		parent::tearDown();
 	}
+
+	/**
+	 * Wrapper method for the `assert_pre_conditions()` method for forward-compatibility with WP 5.9.
+	 */
+	protected function assertPreConditions() {
+		parent::assertPreConditions();
+		$this->assert_pre_conditions();
+	}
+
+	/**
+	 * Wrapper method for the `assert_post_conditions()` method for forward-compatibility with WP 5.9.
+	 */
+	protected function assertPostConditions() {
+		parent::assertPostConditions();
+		$this->assert_post_conditions();
+	}
+
+	/**
+	 * Placeholder method for forward-compatibility with WP 5.9.
+	 */
+	public static function set_up_before_class() {}
+
+	/**
+	 * Placeholder method for forward-compatibility with WP 5.9.
+	 */
+	public static function tear_down_after_class() {}
+
+	/**
+	 * Placeholder method for forward-compatibility with WP 5.9.
+	 */
+	protected function set_up() {}
+
+	/**
+	 * Placeholder method for forward-compatibility with WP 5.9.
+	 */
+	protected function tear_down() {}
+
+	/**
+	 * Placeholder method for forward-compatibility with WP 5.9.
+	 */
+	protected function assert_pre_conditions() {}
+
+	/**
+	 * Placeholder method for forward-compatibility with WP 5.9.
+	 */
+	protected function assert_post_conditions() {}
 }

tests/phpunit/includes/testcase.php

@@ -46,30 +46,80 @@ class WP_UnitTestCase extends WP_UnitTestCase_Base {
 	use ExpectPHPException;
 
 	/**
-	 * Wrapper method for the `setUpBeforeClass()` method for forward-compatibility with WP 5.9.
+	 * Wrapper method for the `set_up_before_class()` method for forward-compatibility with WP 5.9.
 	 */
-	public static function set_up_before_class() {
-		static::setUpBeforeClass();
+	public static function setUpBeforeClass() {
+		parent::setUpBeforeClass();
+		static::set_up_before_class();
 	}
 
 	/**
-	 * Wrapper method for the `tearDownAfterClass()` method for forward-compatibility with WP 5.9.
+	 * Wrapper method for the `tear_down_after_class()` method for forward-compatibility with WP 5.9.
 	 */
-	public static function tear_down_after_class() {
-		static::tearDownAfterClass();
+	public static function tearDownAfterClass() {
+		static::tear_down_after_class();
+		parent::tearDownAfterClass();
 	}
 
 	/**
-	 * Wrapper method for the `setUp()` method for forward-compatibility with WP 5.9.
+	 * Wrapper method for the `set_up()` method for forward-compatibility with WP 5.9.
 	 */
-	public function set_up() {
-		static::setUp();
+	public function setUp() {
+		parent::setUp();
+		$this->set_up();
 	}
 
 	/**
-	 * Wrapper method for the `tearDown()` method for forward-compatibility with WP 5.9.
+	 * Wrapper method for the `tear_down()` method for forward-compatibility with WP 5.9.
 	 */
-	public function tear_down() {
-		static::tearDown();
+	public function tearDown() {
+		$this->tear_down();
+		parent::tearDown();
 	}
+
+	/**
+	 * Wrapper method for the `assert_pre_conditions()` method for forward-compatibility with WP 5.9.
+	 */
+	protected function assertPreConditions() {
+		parent::assertPreConditions();
+		$this->assert_pre_conditions();
+	}
+
+	/**
+	 * Wrapper method for the `assert_post_conditions()` method for forward-compatibility with WP 5.9.
+	 */
+	protected function assertPostConditions() {
+		parent::assertPostConditions();
+		$this->assert_post_conditions();
+	}
+
+	/**
+	 * Placeholder method for forward-compatibility with WP 5.9.
+	 */
+	public static function set_up_before_class() {}
+
+	/**
+	 * Placeholder method for forward-compatibility with WP 5.9.
+	 */
+	public static function tear_down_after_class() {}
+
+	/**
+	 * Placeholder method for forward-compatibility with WP 5.9.
+	 */
+	protected function set_up() {}
+
+	/**
+	 * Placeholder method for forward-compatibility with WP 5.9.
+	 */
+	protected function tear_down() {}
+
+	/**
+	 * Placeholder method for forward-compatibility with WP 5.9.
+	 */
+	protected function assert_pre_conditions() {}
+
+	/**
+	 * Placeholder method for forward-compatibility with WP 5.9.
+	 */
+	protected function assert_post_conditions() {}
 }