Make possible to check if an extension is present, directly in Twig

src/Command/ExtensionsListCommand.php

@@ -37,14 +37,14 @@ protected function execute(InputInterface $input, OutputInterface $output): int
         $rows = [];
 
         foreach ($extensions as $extension) {
-            $rows[] = [$extension->getClass(), $extension->getName()];
+            $rows[] = [$extension->getComposerPackage()->getName(), $extension->getClass(), $extension->getName()];
         }
 
         $io = new SymfonyStyle($input, $output);
 
         if (! empty($rows)) {
             $io->text('Currently installed extensions:');
-            $io->table(['Class', 'Extension name'], $rows);
+            $io->table(['Package name', 'Class', 'Extension name'], $rows);
         } else {
             $io->caution('No installed extensions could be found');
         }

src/Twig/ExtensionExtension.php

@@ -0,0 +1,61 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Bolt\Twig;
+
+use Bolt\Extension\ExtensionRegistry;
+use Tightenco\Collect\Support\Collection;
+use Twig\Extension\AbstractExtension;
+use Twig\TwigFunction;
+
+/**
+ * Widget functionality Twig extension.
+ */
+class ExtensionExtension extends AbstractExtension
+{
+    /** @var ExtensionRegistry */
+    private $registry;
+
+    public function __construct(ExtensionRegistry $registry)
+    {
+        $this->registry = $registry;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getFunctions(): array
+    {
+        return [
+            new TwigFunction('extension_exists', [$this, 'extensionExists']),
+            new TwigFunction('extensions', [$this, 'getExtensions']),
+        ];
+    }
+
+    public function getExtensions(): Collection
+    {
+        $extensions = $this->registry->getExtensions();
+
+        $rows = [];
+
+        foreach ($extensions as $extension) {
+            $rows[] = [
+                'package' => $extension->getComposerPackage()->getName(),
+                'class' => $extension->getClass(),
+                'name' => $extension->getName(),
+            ];
+        }
+
+        return new Collection($rows);
+    }
+
+    public function extensionExists(string $name): bool
+    {
+        $extensions = $this->getExtensions();
+
+        return $extensions->where('package', $name)->isNotEmpty() ||
+            $extensions->where('class', $name)->isNotEmpty() ||
+            $extensions->where('name', $name)->isNotEmpty();
+    }
+}