TestSuiteLoader will always consider classes from the current file

tests/.snapshots/success.txt

@@ -1015,9 +1015,15 @@
    PASS  Tests\PHPUnit\CustomAffixes\snakecasespec
   ✓ it runs file names like snake_case_spec.php
 
+   PASS  Tests\CustomTestCase\ChildTest
+  ✓ override method
+
    PASS  Tests\CustomTestCase\ExecutedTest
   ✓ that gets executed
 
+   PASS  Tests\CustomTestCase\ParentTest
+  ✓ override method
+
    PASS  Tests\PHPUnit\CustomTestCase\UsesPerDirectory
   ✓ closure was bound to CustomTestCase
 
@@ -1210,4 +1216,4 @@
    WARN  Tests\Visual\Version
   - visual snapshot of help command output
 
-  Tests:    2 deprecated, 4 warnings, 5 incomplete, 2 notices, 13 todos, 19 skipped, 860 passed (1975 assertions)
+  Tests:    2 deprecated, 4 warnings, 5 incomplete, 2 notices, 13 todos, 19 skipped, 862 passed (1977 assertions)

tests/.snapshots/todo.txt

@@ -19,7 +19,13 @@
   ↓ something todo later chained
   ↓ something todo later chained and with function body
 
+   PASS  Tests\CustomTestCase\ChildTest
+  ✓ override method
+
    PASS  Tests\CustomTestCase\ExecutedTest
   ✓ that gets executed
 
-  Tests:    13 todos, 1 passed (1 assertions)
+   PASS  Tests\CustomTestCase\ParentTest
+  ✓ override method
+
+  Tests:    13 todos, 3 passed (3 assertions)

tests/PHPUnit/CustomTestCase/ChildTest.php

@@ -0,0 +1,13 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tests\CustomTestCase;
+
+class ChildTest extends ParentTest
+{
+    private function getEntity(): bool
+    {
+        return true;
+    }
+}

tests/PHPUnit/CustomTestCase/ParentTest.php

@@ -0,0 +1,22 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tests\CustomTestCase;
+
+use function PHPUnit\Framework\assertTrue;
+use PHPUnit\Framework\TestCase;
+
+class ParentTest extends TestCase
+{
+    private function getEntity(): bool
+    {
+        return false;
+    }
+
+    /** @test */
+    public function testOverrideMethod(): void
+    {
+        assertTrue($this->getEntity() || true);
+    }
+}

tests/Visual/Parallel.php

@@ -16,7 +16,7 @@ $run = function () {
 
 test('parallel', function () use ($run) {
     expect($run('--exclude-group=integration'))
-        ->toContain('Tests:    1 deprecated, 4 warnings, 5 incomplete, 2 notices, 13 todos, 15 skipped, 849 passed (1960 assertions)')
+        ->toContain('Tests:    1 deprecated, 4 warnings, 5 incomplete, 2 notices, 13 todos, 15 skipped, 851 passed (1962 assertions)')
         ->toContain('Parallel: 3 processes');
 })->skipOnWindows();