MDL-60978 testing: Support ability to run phpunit in isolated process

lib/phpunit/classes/advanced_testcase.php

@@ -56,7 +56,7 @@ abstract class advanced_testcase extends base_testcase {
 
         $this->setBackupGlobals(false);
         $this->setBackupStaticAttributes(false);
-        $this->setRunTestInSeparateProcess(false);
+        $this->setPreserveGlobalState(false);
     }
 
     /**
@@ -490,19 +490,6 @@ abstract class advanced_testcase extends base_testcase {
         return phpunit_util::start_event_redirection();
     }
 
-    /**
-     * Cleanup after all tests are executed.
-     *
-     * Note: do not forget to call this if overridden...
-     *
-     * @static
-     * @return void
-     */
-    public static function tearDownAfterClass() {
-        self::resetAllData();
-    }
-
-
     /**
      * Reset all database tables, restore global state and clear caches and optionally purge dataroot dir.
      *

lib/phpunit/classes/util.php

@@ -881,4 +881,16 @@ class phpunit_util extends testing_util {
         $method->setAccessible(true);
         return $method->invokeArgs($object, $params);
     }
+
+    /**
+     * Whether the current process is an isolated test process.
+     *
+     * @return bool
+     */
+    public static function is_in_isolated_process(): bool {
+        // Note: There is no function to call, or much to go by in order to tell whether we are in an isolated process
+        // during Bootstrap, when this function is called.
+        // We can do so by testing the existence of the wrapper function, but there is nothing set until that point.
+        return function_exists('__phpunit_run_isolated_test');
+    }
 }