symfony
diff --git a/‎src/Symfony/Bundle/FrameworkBundle/Command/TranslationDebugCommand.php
Lines changed: 58 additions & 9 deletions b/‎src/Symfony/Bundle/FrameworkBundle/Command/TranslationDebugCommand.php
Lines changed: 58 additions & 9 deletions
diff --git a/‎src/Symfony/Bundle/FrameworkBundle/Tests/Command/TranslationDebugCommandTest.php
Lines changed: 73 additions & 12 deletions b/‎src/Symfony/Bundle/FrameworkBundle/Tests/Command/TranslationDebugCommandTest.php
Lines changed: 73 additions & 12 deletions
@@ -12,13 +12,17 @@
 namespace Symfony\Bundle\FrameworkBundle\Command;
 
 use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Completion\CompletionInput;
+use Symfony\Component\Console\Completion\CompletionSuggestions;
 use Symfony\Component\Console\Exception\InvalidArgumentException;
 use Symfony\Component\Console\Input\InputArgument;
 use Symfony\Component\Console\Input\InputInterface;
 use Symfony\Component\Console\Input\InputOption;
 use Symfony\Component\Console\Output\OutputInterface;
 use Symfony\Component\Console\Style\SymfonyStyle;
+use Symfony\Component\HttpKernel\Bundle\BundleInterface;
 use Symfony\Component\HttpKernel\KernelInterface;
+use Symfony\Component\Intl\Locales;
 use Symfony\Component\Translation\Catalogue\MergeOperation;
 use Symfony\Component\Translation\DataCollectorTranslator;
 use Symfony\Component\Translation\Extractor\ExtractorInterface;
@@ -135,15 +139,8 @@ protected function execute(InputInterface $input, OutputInterface $output): int
         $kernel = $this->getApplication()->getKernel();
 
         // Define Root Paths
-        $transPaths = $this->transPaths;
-        if ($this->defaultTransPath) {
-            $transPaths[] = $this->defaultTransPath;
-        }
-        $codePaths = $this->codePaths;
-        $codePaths[] = $kernel->getProjectDir().'/src';
-        if ($this->defaultViewsPath) {
-            $codePaths[] = $this->defaultViewsPath;
-        }
+        $transPaths = $this->getRootTransPaths();
+        $codePaths = $this->getRootCodePaths($kernel);
 
         // Override with provided Bundle info
         if (null !== $input->getArgument('bundle')) {
@@ -259,6 +256,37 @@ protected function execute(InputInterface $input, OutputInterface $output): int
         return $exitCode;
     }
 
+    public function complete(CompletionInput $input, CompletionSuggestions $suggestions): void
+    {
+        if ($input->mustSuggestArgumentValuesFor('locale')) {
+            $suggestions->suggestValues(Locales::getLocales());
+
+            return;
+        }
+
+        /** @var KernelInterface $kernel */
+        $kernel = $this->getApplication()->getKernel();
+
+        if ($input->mustSuggestArgumentValuesFor('bundle')) {
+            $suggestions->suggestValues(array_map(function (BundleInterface $bundle) {
+                return $bundle->getName();
+            }, $kernel->getBundles()));
+
+            return;
+        }
+
+        if ($input->mustSuggestOptionValuesFor('domain')) {
+            $locale = $input->getArgument('locale');
+
+            $mergeOperation = new MergeOperation(
+                $this->extractMessages($locale, $this->getRootCodePaths($kernel)),
+                $this->loadCurrentMessages($locale, $this->getRootTransPaths())
+            );
+
+            $suggestions->suggestValues($mergeOperation->getDomains());
+        }
+    }
+
     private function formatState(int $state): string
     {
         if (self::MESSAGE_MISSING === $state) {
@@ -354,4 +382,25 @@ private function loadFallbackCatalogues(string $locale, array $transPaths): arra
 
         return $fallbackCatalogues;
     }
+
+    private function getRootTransPaths(): array
+    {
+        $transPaths = $this->transPaths;
+        if ($this->defaultTransPath) {
+            $transPaths[] = $this->defaultTransPath;
+        }
+
+        return $transPaths;
+    }
+
+    private function getRootCodePaths(KernelInterface $kernel): array
+    {
+        $codePaths = $this->codePaths;
+        $codePaths[] = $kernel->getProjectDir().'/src';
+        if ($this->defaultViewsPath) {
+            $codePaths[] = $this->defaultViewsPath;
+        }
+
+        return $codePaths;
+    }
 }
@@ -14,11 +14,14 @@
 use PHPUnit\Framework\TestCase;
 use Symfony\Bundle\FrameworkBundle\Command\TranslationDebugCommand;
 use Symfony\Bundle\FrameworkBundle\Console\Application;
+use Symfony\Bundle\FrameworkBundle\Tests\Fixtures\BaseBundle\BaseBundle;
+use Symfony\Component\Console\Tester\CommandCompletionTester;
 use Symfony\Component\Console\Tester\CommandTester;
 use Symfony\Component\DependencyInjection\Container;
 use Symfony\Component\Filesystem\Filesystem;
 use Symfony\Component\HttpKernel\Bundle\BundleInterface;
 use Symfony\Component\HttpKernel\KernelInterface;
+use Symfony\Component\Intl\Locales;
 use Symfony\Component\Translation\Extractor\ExtractorInterface;
 use Symfony\Component\Translation\Reader\TranslationReader;
 use Symfony\Component\Translation\Translator;
@@ -139,23 +142,30 @@ protected function tearDown(): void
         $this->fs->remove($this->translationDir);
     }
 
-    private function createCommandTester($extractedMessages = [], $loadedMessages = [], $kernel = null, array $transPaths = [], array $codePaths = []): CommandTester
+    private function createCommandTester(array $extractedMessages = [], array $loadedMessages = [], KernelInterface $kernel = null, array $transPaths = [], array $codePaths = []): CommandTester
+    {
+        return new CommandTester($this->createCommand($extractedMessages, $loadedMessages, $kernel, $transPaths, $codePaths));
+    }
+
+    private function createCommand(array $extractedMessages = [], array $loadedMessages = [], KernelInterface $kernel = null, array $transPaths = [], array $codePaths = [], ExtractorInterface $extractor = null, array $bundles = []): TranslationDebugCommand
     {
         $translator = $this->createMock(Translator::class);
         $translator
             ->expects($this->any())
             ->method('getFallbackLocales')
             ->willReturn(['en']);
 
-        $extractor = $this->createMock(ExtractorInterface::class);
-        $extractor
-            ->expects($this->any())
-            ->method('extract')
-            ->willReturnCallback(
-                function ($path, $catalogue) use ($extractedMessages) {
-                    $catalogue->add($extractedMessages);
-                }
-            );
+        if (!$extractor) {
+            $extractor = $this->createMock(ExtractorInterface::class);
+            $extractor
+                ->expects($this->any())
+                ->method('extract')
+                ->willReturnCallback(
+                    function ($path, $catalogue) use ($extractedMessages) {
+                        $catalogue->add($extractedMessages);
+                    }
+                );
+        }
 
         $loader = $this->createMock(TranslationReader::class);
         $loader
@@ -182,7 +192,7 @@ function ($path, $catalogue) use ($loadedMessages) {
         $kernel
             ->expects($this->any())
             ->method('getBundles')
-            ->willReturn([]);
+            ->willReturn($bundles);
 
         $container = new Container();
         $kernel
@@ -195,7 +205,7 @@ function ($path, $catalogue) use ($loadedMessages) {
         $application = new Application($kernel);
         $application->add($command);
 
-        return new CommandTester($application->find('debug:translation'));
+        return $application->find('debug:translation');
     }
 
     private function getBundle($path)
@@ -209,4 +219,55 @@ private function getBundle($path)
 
         return $bundle;
     }
+
+    /**
+     * @dataProvider provideCompletionSuggestions
+     */
+    public function testComplete(array $input, array $expectedSuggestions)
+    {
+        $extractedMessagesWithDomains = [
+            'messages' => [
+                'foo' => 'foo',
+            ],
+            'validators' => [
+                'foo' => 'foo',
+            ],
+            'custom_domain' => [
+                'foo' => 'foo',
+            ],
+        ];
+        $extractor = $this->createMock(ExtractorInterface::class);
+        $extractor
+            ->expects($this->any())
+            ->method('extract')
+            ->willReturnCallback(
+                function ($path, $catalogue) use ($extractedMessagesWithDomains) {
+                    foreach ($extractedMessagesWithDomains as $domain => $message) {
+                        $catalogue->add($message, $domain);
+                    }
+                }
+            );
+
+        $tester = new CommandCompletionTester($this->createCommand([], [], null, [], [], $extractor, [new BaseBundle()]));
+        $suggestions = $tester->complete($input);
+        $this->assertSame($expectedSuggestions, $suggestions);
+    }
+
+    public function provideCompletionSuggestions()
+    {
+        yield 'locale' => [
+            [''],
+            Locales::getLocales(),
+        ];
+
+        yield 'bundle' => [
+            ['fr', '--domain', 'messages', ''],
+            ['BaseBundle'],
+        ];
+
+        yield 'option --domain' => [
+            ['en', '--domain', ''],
+            ['messages', 'validators', 'custom_domain'],
+        ];
+    }
 }