Add phpunit compat file back.

Author: octalmage

tests/phpunit/bootstrap.php

@@ -21,6 +21,10 @@
 	$test_root = '../../../../../../../tests/phpunit';
 }
 
+if ( version_compare( getenv( 'WP_VERSION' ), '4.8', '<' ) && class_exists( 'PHPUnit\Runner\Version' ) ) {
+	require_once dirname( __FILE__ ) . '/phpunit6-compat.php';
+}
+
 if ( file_exists( $test_root . '/includes/functions.php' ) ) {
 	require_once $test_root . '/includes/functions.php';
 	function _manually_load_plugin() {

tests/phpunit/phpunit6-compat.php

@@ -0,0 +1,28 @@
+<?php
+if ( class_exists( 'PHPUnit\Runner\Version' ) && version_compare( PHPUnit\Runner\Version::id(), '6.0', '>=' ) ) {
+	class_alias( 'PHPUnit\Framework\TestCase',                   'PHPUnit_Framework_TestCase' );
+	class_alias( 'PHPUnit\Framework\Exception',                  'PHPUnit_Framework_Exception' );
+	class_alias( 'PHPUnit\Framework\ExpectationFailedException', 'PHPUnit_Framework_ExpectationFailedException' );
+	class_alias( 'PHPUnit\Framework\Error\Notice',               'PHPUnit_Framework_Error_Notice' );
+	class_alias( 'PHPUnit\Framework\Error\Warning',              'PHPUnit_Framework_Error_Warning' );
+	class_alias( 'PHPUnit\Framework\Test',                       'PHPUnit_Framework_Test' );
+	class_alias( 'PHPUnit\Framework\Warning',                    'PHPUnit_Framework_Warning' );
+	class_alias( 'PHPUnit\Framework\AssertionFailedError',       'PHPUnit_Framework_AssertionFailedError' );
+	class_alias( 'PHPUnit\Framework\TestSuite',                  'PHPUnit_Framework_TestSuite' );
+	class_alias( 'PHPUnit\Framework\TestListener',               'PHPUnit_Framework_TestListener' );
+	class_alias( 'PHPUnit\Util\GlobalState',                     'PHPUnit_Util_GlobalState' );
+	class_alias( 'PHPUnit\Util\Getopt',                          'PHPUnit_Util_Getopt' );
+	class PHPUnit_Util_Test extends PHPUnit\Util\Test {
+		public static function getTickets( $className, $methodName ) {
+			$annotations = self::parseTestMethodAnnotations( $className, $methodName );
+			$tickets = array();
+			if ( isset( $annotations['class']['ticket'] ) ) {
+				$tickets = $annotations['class']['ticket'];
+			}
+			if ( isset( $annotations['method']['ticket'] ) ) {
+				$tickets = array_merge( $tickets, $annotations['method']['ticket'] );
+			}
+			return array_unique( $tickets );
+		}
+	}
+}