[generator] make import tests into a unit test

When we run safe with multiple different PHP versions, we want to make sure importing the library works under all versions - not just the version we generate with

generator/src/GenerateCommand.php

@@ -53,26 +53,6 @@ protected function execute(InputInterface $input, OutputInterface $output): int
 
         $this->runCsFix($output);
 
-        // Let's require the generated file to check there is no error.
-        $files = \glob(__DIR__.'/../../generated/*.php');
-        if ($files === false) {
-            throw new \RuntimeException('Failed to require the generated file');
-        }
-
-        foreach ($files as $file) {
-            require($file);
-        }
-
-        $files = \glob(__DIR__.'/../../generated/Exceptions/*.php');
-        if ($files === false) {
-            throw new \RuntimeException('Failed to require the generated exception file');
-        }
-
-        require_once __DIR__.'/../../lib/Exceptions/SafeExceptionInterface.php';
-        foreach ($files as $file) {
-            require($file);
-        }
-
         // Finally, let's edit the composer.json file
         $output->writeln('Editing composer.json');
         ComposerJsonEditor::editComposerFileForGeneration(\array_values($modules));

tests/GeneratedFilesTest.php

@@ -0,0 +1,42 @@
+<?php
+
+declare(strict_types=1);
+
+use PHPUnit\Framework\TestCase;
+
+final class GeneratedFilesTest extends TestCase
+{
+    public function testRequireModules(): void
+    {
+        self::expectNotToPerformAssertions();
+
+        $files = \glob(__DIR__.'/../generated/*.php');
+        if ($files === false) {
+            throw new \RuntimeException('Failed to require the generated file');
+        }
+
+        foreach ($files as $file) {
+            require_once($file);
+        }
+    }
+
+    public function testRequireExceptions(): void
+    {
+        self::expectNotToPerformAssertions();
+
+        $files = \glob(__DIR__.'/../generated/Exceptions/*.php');
+        if ($files === false) {
+            throw new \RuntimeException('Failed to require the generated exception file');
+        }
+        foreach ($files as $file) {
+            require_once($file);
+        }
+    }
+
+    public function testRequireExceptionInterface(): void
+    {
+        self::expectNotToPerformAssertions();
+
+        require_once __DIR__.'/../lib/Exceptions/SafeExceptionInterface.php';
+    }
+}