[Tests] Added coverage for configuring parallel run

Author: alongosz

tests/lib/PhpCsFixer/InternalConfigFactoryTest.php

@@ -11,6 +11,7 @@
 use Ibexa\CodeStyle\PhpCsFixer\InternalConfigFactory;
 use Ibexa\CodeStyle\PhpCsFixer\Sets\Ibexa46RuleSet;
 use Ibexa\CodeStyle\PhpCsFixer\Sets\Ibexa50RuleSet;
+use PhpCsFixer\ParallelAwareConfigInterface;
 use PHPUnit\Framework\TestCase;
 use ReflectionClass;
 use ReflectionMethod;
@@ -40,6 +41,8 @@ protected function setUp(): void
      *
      * @param array{name: string, version: string, pretty_version?: string} $package
      * @param class-string $expectedRuleSetClass
+     *
+     * @throws \ReflectionException
      */
     public function testVersionBasedRuleSetSelection(
         array $package,
@@ -98,4 +101,25 @@ public function testWithRuleSet(): void
 
         self::assertSame($customRuleSet, $this->factory->getRuleSet());
     }
+
+    public function testRunInParallel(): void
+    {
+        // Note: sequential test instead of separate test cases on purpose
+
+        // sanity check
+        /** @var ParallelAwareConfigInterface $config */
+        $config = $this->factory->buildConfig();
+        self::assertSame(1, $config->getParallelConfig()->getMaxProcesses());
+
+        $this->factory->runInParallel();
+        /** @var ParallelAwareConfigInterface $config */
+        $config = $this->factory->buildConfig();
+        self::assertGreaterThan(1, $config->getParallelConfig()->getMaxProcesses());
+
+        // reset test
+        $this->factory->runInParallel(false);
+        /** @var ParallelAwareConfigInterface $config */
+        $config = $this->factory->buildConfig();
+        self::assertSame(1, $config->getParallelConfig()->getMaxProcesses());
+    }
 }