Fix legacy test

Author: IonBazan

src/PackageDiff.php

@@ -230,6 +230,7 @@ private function getFileContents($path, $lockFile = true)
                 throw new \RuntimeException(sprintf('Could not open file %s or find it in git as %s: %s', $originalPath, $path, $outputString));
             }
 
+            /* @infection-ignore-all False-positive */
             return '{}'; // Do not throw exception for composer.json as it might not exist and that's fine
         }
 

tests/Integration/DiffCommandTest.php

@@ -44,7 +44,10 @@ public function testComposerApplication($expectedOutput, array $input)
         $app->setIO(new NullIO()); // For Composer v1
         $app->setAutoExit(false);
         $plugin = $this->getPluginPackage();
-        $config = array('allow-plugins' => array($plugin->getName() => true));
+        $config = array(
+            'allow-plugins' => array($plugin->getName() => true),
+            'github-oauth' => array('github.com' => 'dummy'),
+        );
         $composer = Factory::create($app->getIO(), array('config' => $config), true);
         $app->setComposer($composer);
         $pm = new PluginManager($app->getIO(), $composer);