feat(discovery): support closures in #[SkipDiscovery]

packages/core/src/Kernel/LoadDiscoveryClasses.php

@@ -4,6 +4,7 @@
 
 namespace Tempest\Core\Kernel;
 
+use Exception;
 use Tempest\Container\Container;
 use Tempest\Core\DiscoveryCache;
 use Tempest\Core\DiscoveryCacheStrategy;
@@ -198,11 +199,27 @@ private function scan(DiscoveryLocation $location, array $discoveries, string $p
                 // Resolve `#[SkipDiscovery]` for this class
                 $skipDiscovery = $input->getAttribute(SkipDiscovery::class);
 
-                if ($skipDiscovery !== null && $skipDiscovery->except === []) {
-                    $this->shouldSkipForClass[$className] = true;
-                } elseif ($skipDiscovery !== null) {
-                    foreach ($skipDiscovery->except as $except) {
-                        $this->shouldSkipForClass[$className][$except] = true;
+                if ($skipDiscovery !== null) {
+                    $when = false;
+                    // Evaluate conditional skip
+                    if ($skipDiscovery->when !== null) {
+                        try {
+                            $when = (bool) $this->container->invoke($skipDiscovery->when);
+                        } catch (Throwable $throw) {
+                            throw new Exception($throw->getMessage(), 0, $throw);
+                        }
+                    }
+
+                    $shouldApply = $skipDiscovery->when === null || $when;
+
+                    if ($shouldApply) {
+                        if ($skipDiscovery->except === []) {
+                            $this->shouldSkipForClass[$className] = true;
+                        } else {
+                            foreach ($skipDiscovery->except as $except) {
+                                $this->shouldSkipForClass[$className][$except] = true;
+                            }
+                        }
                     }
                 }
 

packages/discovery/src/SkipDiscovery.php

@@ -5,6 +5,7 @@
 namespace Tempest\Discovery;
 
 use Attribute;
+use Closure;
 
 /**
  * Instruct Tempest to not discover this class.
@@ -15,8 +16,10 @@
     public function __construct(
         /**
          * Allows the specified `Discovery` classes to still discover this class.
-         * @var array<class-string<\Tempest\Discovery\Discovery>>
+         * @param array<class-string<\Tempest\Discovery\Discovery>>
+         * @param Closure|null
          */
         public array $except = [],
+        public ?Closure $when = null,
     ) {}
 }

tests/Fixtures/Discovery/ConditionallyHiddenDatabaseMigration.php

@@ -0,0 +1,26 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tests\Tempest\Fixtures\Discovery;
+
+use Symfony\Component\Console\Application;
+use Tempest\Console\ConsoleApplication;
+use Tempest\Database\MigratesUp;
+use Tempest\Database\QueryStatement;
+use Tempest\Database\QueryStatements\CreateTableStatement;
+use Tempest\Discovery\SkipDiscovery;
+
+#[SkipDiscovery(when: static function (Application $application): bool {
+    return ! $application instanceof ConsoleApplication;
+})]
+final class ConditionallyHiddenDatabaseMigration implements MigratesUp
+{
+    private(set) string $name = 'conditionally-hidden-migration';
+
+    public function up(): QueryStatement
+    {
+        return new CreateTableStatement('hidden')
+            ->primary();
+    }
+}

tests/Integration/Core/LoadDiscoveryClassesTest.php

@@ -10,6 +10,7 @@
 use Tempest\Database\Migrations\RunnableMigrations;
 use Tempest\Discovery\DiscoveryLocation;
 use Tempest\Support\Arr;
+use Tests\Tempest\Fixtures\Discovery\ConditionallyHiddenDatabaseMigration;
 use Tests\Tempest\Fixtures\Discovery\HiddenDatabaseMigration;
 use Tests\Tempest\Fixtures\Discovery\HiddenMigratableDatabaseMigration;
 use Tests\Tempest\Fixtures\GlobalHiddenDiscovery;
@@ -81,4 +82,11 @@ public function only_load_specific_discovery_classes(): void
 
         $this->assertTrue($dependency->discovered);
     }
+
+    #[Test]
+    public function does_not_load_conditionally_hidden_classes(): void
+    {
+        $migrations = $this->container->get(RunnableMigrations::class);
+        $this->assertFalse(Arr\contains($migrations, fn ($m) => $m instanceof ConditionallyHiddenDatabaseMigration));
+    }
 }