add plugin integration test run

Author: IonBazan

.github/workflows/test.yml

@@ -21,6 +21,9 @@ jobs:
           - '8.0'
           - '8.1'
         include:
+          - php-versions: '7.0'
+            composer-flags: '--prefer-lowest'
+            operating-system: ubuntu-latest
           - php-versions: '5.3'
             composer-flags: '--prefer-lowest'
             operating-system: ubuntu-latest

phpunit.xml.dist

@@ -16,6 +16,7 @@
 >
     <php>
         <env name="SYMFONY_DEPRECATIONS_HELPER" value="weak"/>
+        <env name="COMPOSER_DISABLE_XDEBUG_WARN" value="1"/>
     </php>
     <testsuites>
         <testsuite name="Composer Diff Test Suite">

tests/Integration/DiffCommandTest.php

@@ -2,9 +2,14 @@
 
 namespace IonBazan\ComposerDiff\Tests\Integration;
 
+use Composer\Composer;
+use Composer\Console\Application;
+use Composer\IO\IOInterface;
+use Composer\IO\NullIO;
 use IonBazan\ComposerDiff\Command\DiffCommand;
 use IonBazan\ComposerDiff\PackageDiff;
 use IonBazan\ComposerDiff\Tests\TestCase;
+use Symfony\Component\Console\Tester\ApplicationTester;
 use Symfony\Component\Console\Tester\CommandTester;
 
 class DiffCommandTest extends TestCase
@@ -22,6 +27,29 @@ public function testCommand($expectedOutput, array $input)
         $this->assertSame($expectedOutput, $tester->getDisplay());
     }
 
+    /**
+     * @param string $expectedOutput
+     *
+     * @dataProvider commandArgumentsDataProvider
+     */
+    public function testComposerApplication($expectedOutput, array $input)
+    {
+        if (version_compare('2.0', Composer::VERSION, '>=')) {
+            $this->markTestSkipped('This test works properly only on Composer 2');
+        }
+
+        array_unshift($input, 'diff');
+        $app = new ComposerApplication();
+        $app->setIO(new NullIO());
+        $app->setAutoExit(false);
+        $composer = $app->getComposer();
+        $composer->getPluginManager()->registerPackage($composer->getPackage(), true);
+        $tester = new ApplicationTester($app);
+        $result = $tester->run($input);
+        $this->assertSame(0, $result);
+        $this->assertSame($expectedOutput, $tester->getDisplay());
+    }
+
     public function commandArgumentsDataProvider()
     {
         return array(
@@ -194,3 +222,11 @@ public function commandArgumentsDataProvider()
         );
     }
 }
+
+class ComposerApplication extends Application
+{
+    public function setIO(IOInterface $io)
+    {
+        $this->io = $io;
+    }
+}