Get tests passing

src/Console/Command/GenerateCommand.php

@@ -43,6 +43,8 @@ class GenerateCommand extends Command
         } catch (IOException $e) {
             $io->error($e->getMessage());
         }
+
+        return Command::SUCCESS;
     }
 
     private function outputFile(InputInterface $input): string

tests/Unit/Console/Command/GenerateFiltersTest.php

@@ -19,7 +19,7 @@ class GenerateFiltersTest extends TestCase
     /** @var Filesystem */
     private $fs;
 
-    protected function setUp()
+    protected function setUp(): void
     {
         parent::setUp();
 
@@ -32,7 +32,7 @@ class GenerateFiltersTest extends TestCase
         chdir(self::TEST_OUTPUT_DIR);
     }
 
-    protected function tearDown()
+    protected function tearDown(): void
     {
         chdir('..');
         $this->fs->remove(self::TEST_OUTPUT_DIR);

tests/Unit/Model/FilterTest.php

@@ -20,7 +20,7 @@ class FilterTest extends TestCase
     /**
      * {@inheritdoc}
      */
-    public function setUp()
+    public function setUp(): void
     {
         $this->filter = new Filter();
     }