Add functional test for dry run mode

.gitignore

@@ -2,6 +2,7 @@
 /.idea
 /build
 /docker/db-data
+/tests/functional/Resources/var
 /vendor
 /.env
 /.phpunit.result.cache

tests/functional/Dumper/MysqlDumperTest.php

@@ -18,7 +18,7 @@ class MysqlDumperTest extends TestCase
      */
     protected function setUp(): void
     {
-        $this->dumpFile = $this->getResource('db/dump.sql');
+        $this->dumpFile = $this->getResource('var/dump.sql');
     }
 
     /**
@@ -54,6 +54,23 @@ public function testDumper(): void
         $this->assertDumpIsValid(false);
     }
 
+    /**
+     * Assert that the dry run mode works properly.
+     */
+    public function testDryRun(): void
+    {
+        $config = $this->createConfig();
+        $dumper = $this->createDumper();
+
+        // Make sure the dump file does not exist
+        if (file_exists($this->dumpFile)) {
+            unlink($this->dumpFile);
+        }
+
+        $dumper->dump($config, true);
+        $this->assertFileDoesNotExist($this->dumpFile);
+    }
+
     /**
      * Assert that the dump file contents match the dump configuration file.
      */