test(plugin): compare plugin-provided command execution against upstream

A Shirabe-authored CommandProvider fixture plugin (greet) runs under both
implementations: exit codes, the command's own output, help/list rendering,
alias resolution, a validation failure, and a file recording the shared
object graph the command observed (root package, strict application FQCN,
and the exit code of the built-in about command it invoked) must match.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

5 files changed, 132 insertions, 0 deletions

diff --git a/crates/shirabe/tests/plugin/fixtures/e2e-command/plugin/composer.json b/crates/shirabe/tests/plugin/fixtures/e2e-command/plugin/composer.json
new file mode 100644
index 00000000..76cf19e9
--- /dev/null
+++ b/crates/shirabe/tests/plugin/fixtures/e2e-command/plugin/composer.json
@@ -0,0 +1,17 @@
+{
+    "name": "shirabe-test/command-provider",
+    "version": "1.0.0",
+    "type": "composer-plugin",
+    "description": "Fixture plugin providing a command through the CommandProvider capability.",
+    "autoload": {
+        "psr-4": {
+            "ShirabeTest\\CommandProvider\\": "src/"
+        }
+    },
+    "require": {
+        "composer-plugin-api": "^2.0"
+    },
+    "extra": {
+        "class": "ShirabeTest\\CommandProvider\\Plugin"
+    }
+}
diff --git a/crates/shirabe/tests/plugin/fixtures/e2e-command/plugin/src/GreetCommand.php b/crates/shirabe/tests/plugin/fixtures/e2e-command/plugin/src/GreetCommand.php
new file mode 100644
index 00000000..51b3e765
--- /dev/null
+++ b/crates/shirabe/tests/plugin/fixtures/e2e-command/plugin/src/GreetCommand.php
@@ -0,0 +1,48 @@
+<?php
+
+namespace ShirabeTest\CommandProvider;
+
+use Composer\Command\BaseCommand;
+use Symfony\Component\Console\Input\ArrayInput;
+use Symfony\Component\Console\Input\InputArgument;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Input\InputOption;
+use Symfony\Component\Console\Output\OutputInterface;
+
+class GreetCommand extends BaseCommand
+{
+    protected function configure(): void
+    {
+        $this
+            ->setName('greet')
+            ->setAliases(['hi'])
+            ->setDescription('Greets someone from a plugin-provided command.')
+            ->setHelp('The <info>greet</info> command exercises plugin-provided command execution.')
+            ->addArgument('who', InputArgument::REQUIRED, 'Who to greet')
+            ->addOption('shout', 's', InputOption::VALUE_NONE, 'Uppercase the greeting')
+            ->addOption('out', null, InputOption::VALUE_REQUIRED, 'File the command writes its observations to');
+    }
+
+    protected function execute(InputInterface $input, OutputInterface $output): int
+    {
+        $message = 'Hello ' . $input->getArgument('who');
+        if ($input->getOption('shout')) {
+            $message = strtoupper($message);
+        }
+        $this->getIO()->write('greet: ' . $message);
+
+        $composer = $this->requireComposer();
+        $lines = [
+            'root=' . $composer->getPackage()->getName(),
+            'app=' . get_class($this->getApplication()),
+        ];
+        $aboutExit = $this->getApplication()->find('about')->run(new ArrayInput(['command' => 'about']), $output);
+        $lines[] = 'about=' . $aboutExit;
+        $out = $input->getOption('out');
+        if ($out !== null) {
+            file_put_contents($out, implode("\n", $lines) . "\n");
+        }
+
+        return 0;
+    }
+}
diff --git a/crates/shirabe/tests/plugin/fixtures/e2e-command/plugin/src/GreetCommandProvider.php b/crates/shirabe/tests/plugin/fixtures/e2e-command/plugin/src/GreetCommandProvider.php
new file mode 100644
index 00000000..ce36e062
--- /dev/null
+++ b/crates/shirabe/tests/plugin/fixtures/e2e-command/plugin/src/GreetCommandProvider.php
@@ -0,0 +1,13 @@
+<?php
+
+namespace ShirabeTest\CommandProvider;
+
+use Composer\Plugin\Capability\CommandProvider as CommandProviderCapability;
+
+class GreetCommandProvider implements CommandProviderCapability
+{
+    public function getCommands(): array
+    {
+        return [new GreetCommand()];
+    }
+}
diff --git a/crates/shirabe/tests/plugin/fixtures/e2e-command/plugin/src/Plugin.php b/crates/shirabe/tests/plugin/fixtures/e2e-command/plugin/src/Plugin.php
new file mode 100644
index 00000000..fc708b1f
--- /dev/null
+++ b/crates/shirabe/tests/plugin/fixtures/e2e-command/plugin/src/Plugin.php
@@ -0,0 +1,30 @@
+<?php
+
+namespace ShirabeTest\CommandProvider;
+
+use Composer\Composer;
+use Composer\IO\IOInterface;
+use Composer\Plugin\Capable;
+use Composer\Plugin\PluginInterface;
+
+class Plugin implements PluginInterface, Capable
+{
+    public function activate(Composer $composer, IOInterface $io): void
+    {
+    }
+
+    public function deactivate(Composer $composer, IOInterface $io): void
+    {
+    }
+
+    public function uninstall(Composer $composer, IOInterface $io): void
+    {
+    }
+
+    public function getCapabilities(): array
+    {
+        return [
+            'Composer\Plugin\Capability\CommandProvider' => GreetCommandProvider::class,
+        ];
+    }
+}
diff --git a/crates/shirabe/tests/plugin/fixtures/e2e-command/project/composer.json b/crates/shirabe/tests/plugin/fixtures/e2e-command/project/composer.json
new file mode 100644
index 00000000..e68a53de
--- /dev/null
+++ b/crates/shirabe/tests/plugin/fixtures/e2e-command/project/composer.json
@@ -0,0 +1,24 @@
+{
+    "name": "shirabe/e2e-command-provider",
+    "description": "E2E fixture project: run a plugin-provided command against upstream Composer and Shirabe.",
+    "repositories": [
+        {
+            "type": "path",
+            "url": "../plugin",
+            "options": {
+                "symlink": false
+            }
+        },
+        {
+            "packagist.org": false
+        }
+    ],
+    "require": {
+        "shirabe-test/command-provider": "1.0.0"
+    },
+    "config": {
+        "allow-plugins": {
+            "shirabe-test/command-provider": true
+        }
+    }
+}