Proposed solution for #5457 gherkin scenarios not loaded from group file

src/Codeception/Lib/GroupManager.php

@@ -5,6 +5,7 @@
 use Codeception\Test\Interfaces\Reported;
 use Codeception\Test\Descriptor;
 use Codeception\TestInterface;
+use Codeception\Test\Gherkin;
 use Symfony\Component\Finder\Finder;
 use Symfony\Component\Finder\SplFileInfo;
 
@@ -118,6 +119,10 @@ public function groupsForTest(\PHPUnit\Framework\Test $test)
                 if (strpos($filename . ':' . $test->getName(false), $testPattern) === 0) {
                     $groups[] = $group;
                 }
+                if ($test instanceof Gherkin
+                    && mb_strtolower($filename . ':' . $test->getMetadata()->getFeature()) === mb_strtolower($testPattern)) {
+                    $groups[] = $group;
+                }
                 if ($test instanceof \PHPUnit\Framework\TestSuite\DataProvider) {
                     $firstTest = $test->testAt(0);
                     if ($firstTest != false && $firstTest instanceof TestInterface) {

tests/data/gherkinGroup1

@@ -0,0 +1 @@
+tests/data/refund.feature:Jeff returns a faulty microwave

tests/data/gherkinGroup2

@@ -0,0 +1 @@
+tests/data/refund2.feature:ジェフは不完全な電子レンジを返します

tests/data/refund2.feature

@@ -0,0 +1,10 @@
+@important
+Feature: Refund item
+  In order to get satisfaction
+  As a customer
+  I need to be able to get refunds
+
+  Scenario: ジェフは不完全な電子レンジを返します
+    Given Jeff has bought a microwave for "$100"
+    When he returns the microwave
+    Then Jeff should be refunded $100

tests/unit/Codeception/Lib/GroupManagerTest.php

@@ -2,6 +2,7 @@
 namespace Codeception\Lib;
 
 use Codeception\Util\Stub;
+use Codeception\Test\Loader\Gherkin as GherkinLoader;
 
 class GroupManagerTest extends \Codeception\Test\Unit
 {
@@ -75,6 +76,24 @@ public function testGroupsFileHandlesWhitespace()
         $this->assertEmpty($this->manager->groupsForTest($badTest));
     }
 
+    public function testLoadSpecificScenarioFromFile()
+    {
+        $this->manager = new GroupManager(['gherkinGroup1' => 'tests/data/gherkinGroup1']);
+        $loader = new GherkinLoader();
+        $loader->loadTests(codecept_absolute_path('tests/data/refund.feature'));
+        $test = $loader->getTests()[0];
+        $this->assertContains('gherkinGroup1', $this->manager->groupsForTest($test));
+    }
+
+    public function testLoadSpecificScenarioWithMultibyteStringFromFile()
+    {
+        $this->manager = new GroupManager(['gherkinGroup2' => 'tests/data/gherkinGroup2']);
+        $loader = new GherkinLoader();
+        $loader->loadTests(codecept_absolute_path('tests/data/refund2.feature'));
+        $test = $loader->getTests()[0];
+        $this->assertContains('gherkinGroup2', $this->manager->groupsForTest($test));
+    }
+
     protected function makeTestCase($file, $name = '')
     {
         return Stub::make(