fix: library entries read as not found without the library right (P12)

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

src/Integrations/Divi/Library/LibraryAccess.php

@@ -51,7 +51,9 @@ class LibraryAccess
     /**
      * The library entry $postId after the checks for reading, or their refusal; null when $postId
      * names no library entry (the caller goes on with PostGuard). With the library hidden (ruling
-     * P9), an entry is refused exactly like an ID that does not exist – before any rights check.
+     * P9) or without the library right at all (ruling P12), an entry is refused exactly like an ID
+     * that does not exist, so its type and existence stay unknown; only a user with the library
+     * right who lacks edit_post on the entry gets forbidden (like pages).
      */
     public function item(mixed $postId, bool $forWrite): WP_Post|WP_Error|null
     {
@@ -61,7 +63,7 @@ class LibraryAccess
             return null;
         }
 
-        if ($this->visible !== null && ! ($this->visible)()) {
+        if (($this->visible !== null && ! ($this->visible)()) || $this->canList() !== null) {
             return PostGuard::notFound((int) $post->ID);
         }
 

tests/Unit/Integrations/Divi/DiviIntegrationTest.php

@@ -66,10 +66,17 @@ final class DiviIntegrationTest extends TestCase
         $schema->allows('isManaged')->andReturn(false);
         $outline = static fn (DiviIntegration $divi): mixed => $divi->abilities()[0]->permission(['post_id' => 1055]);
 
-        // No Divi in unit tests: DiviRoles allows nothing, so a reachable entry is refused, not missing.
-        $visible = new DiviIntegration($schema, FakeChangeLog::forbidden(), null, static fn (): bool => true);
-        self::assertToolError($outline($visible), 'forbidden');
-        self::assertToolError($outline(new DiviIntegration($schema, FakeChangeLog::forbidden())), 'forbidden');
+        // No Divi in unit tests: DiviRoles allows nothing, so the entry is not found either way (ruling P12);
+        // the wiring shows in which gate the integration asks.
+        $asked = 0;
+        $visible = new DiviIntegration($schema, FakeChangeLog::forbidden(), null, static function () use (&$asked): bool {
+            ++$asked;
+
+            return true;
+        });
+        self::assertToolError($outline($visible), 'not_found');
+        self::assertSame(1, $asked);
+        self::assertToolError($outline(new DiviIntegration($schema, FakeChangeLog::forbidden())), 'not_found');
 
         $hidden = new DiviIntegration($schema, FakeChangeLog::forbidden(), libraryVisible: static fn (): bool => false);
         $refusal = $outline($hidden);

tests/Unit/Integrations/Divi/Library/LibraryAccessTest.php

@@ -5,8 +5,12 @@ declare(strict_types=1);
 namespace LIT\MCP\Tests\Unit\Integrations\Divi\Library;
 
 use LIT\MCP\Integrations\Divi\Library\LibraryAccess;
+use LIT\MCP\Integrations\WordPress\PostGuard;
+use LIT\MCP\Integrations\WordPress\Schema\ContentSchema;
 use LIT\MCP\Tests\Support\LibraryFixtures;
 use LIT\MCP\Tests\Unit\TestCase;
+use Mockery;
+use WP_Error;
 use WP_Post;
 
 final class LibraryAccessTest extends TestCase
@@ -24,15 +28,18 @@ final class LibraryAccessTest extends TestCase
         self::assertNull($access->canList());
     }
 
+    /** Ruling P12: without the library right at all, library IDs read like missing IDs (no type oracle). */
     public function testReadingNeedsEditPostsTheDiviLibraryRoleAndEditPost(): void
     {
         $item = LibraryFixtures::item(1055);
 
         LibraryFixtures::given([$item], ['edit_posts']);
-        self::assertToolError(LibraryFixtures::access()->item(1055, false), 'forbidden');
+        self::assertToolError(LibraryFixtures::access()->item(1055, false), 'not_found');
+        self::assertToolError(LibraryFixtures::access()->canList(), 'forbidden');
 
         LibraryFixtures::given([$item]);
-        self::assertToolError(LibraryFixtures::access(['divi_library'])->item(1055, false), 'forbidden');
+        self::assertToolError(LibraryFixtures::access(['divi_library'])->item(1055, false), 'not_found');
+        self::assertToolError(LibraryFixtures::access(['divi_library'])->canList(), 'forbidden');
 
         LibraryFixtures::given([$item], ['edit_post']);
         $refusal = LibraryFixtures::access()->item(1055, false);
@@ -63,7 +70,7 @@ final class LibraryAccessTest extends TestCase
         foreach ([['edit_posts'], ['edit_post']] as $denied) {
             LibraryFixtures::given([$item], $denied);
             $refusal = LibraryFixtures::access()->item(1055, false);
-            self::assertToolError($refusal, 'forbidden');
+            self::assertToolError($refusal, $denied === ['edit_post'] ? 'forbidden' : 'not_found');
             self::assertStringNotContainsString('Geheimer Entwurf', $refusal->get_error_message());
             self::assertStringNotContainsString('Geheimer Entwurf', (string) wp_json_encode($refusal->get_error_data()));
         }
@@ -85,4 +92,25 @@ final class LibraryAccessTest extends TestCase
         self::assertNull($hidden->item(LibraryFixtures::PAGE, false), 'pages stay PostGuard\'s business');
         self::assertNull($hidden->item(9999, false));
     }
+
+    /** Ruling P12: the refusal without the library right is byte-identical to a missing ID's. */
+    public function testWithoutTheLibraryRightAnEntryIsIndistinguishableFromAMissingId(): void
+    {
+        $schema = Mockery::mock(ContentSchema::class);
+        $schema->allows('isManaged')->andReturn(false);
+
+        foreach ([[['edit_posts'], []], [[], ['divi_library']]] as [$denied, $deniedRoles]) {
+            LibraryFixtures::given([LibraryFixtures::item(1055, ['post_title' => 'Geheimer Entwurf'])], $denied);
+            $refusal = LibraryFixtures::access($deniedRoles)->item(1055, false);
+
+            LibraryFixtures::given([], $denied);
+            $missing = PostGuard::editable(1055, $schema, 'post_id', true);
+
+            self::assertInstanceOf(WP_Error::class, $refusal);
+            self::assertInstanceOf(WP_Error::class, $missing);
+            self::assertSame($missing->get_error_code(), $refusal->get_error_code());
+            self::assertSame($missing->get_error_message(), $refusal->get_error_message());
+            self::assertSame($missing->get_error_data(), $refusal->get_error_data());
+        }
+    }
 }

tests/Unit/Integrations/Divi/Pages/DiviPageLoaderTest.php

@@ -123,7 +123,7 @@ final class DiviPageLoaderTest extends TestCase
         self::assertToolError((new DiviPageLoader($schema))->load(1058, false), 'not_found');
         self::assertToolError(
             (new DiviPageLoader($schema, new Parser(), LibraryFixtures::access(['divi_library'])))->load(1058, false),
-            'forbidden'
+            'not_found'
         );
     }
 

tests/Unit/Integrations/Divi/Pages/DiviReadAbilitiesTest.php

@@ -152,7 +152,7 @@ final class DiviReadAbilitiesTest extends TestCase
         self::assertSame('https://kunde.test/wp-admin/post.php?post=1059&action=edit', $result['edit_url']);
     }
 
-    public function testNodeGetOfALibraryItemAndRefusalsWithoutTheLibraryRight(): void
+    public function testNodeGetOfALibraryItemAndNotFoundWithoutTheLibraryRight(): void
     {
         LibraryFixtures::given([LibraryFixtures::item(1057, ['post_status' => 'private', 'post_title' => 'Geheim'])]);
         $ability = new DiviNodeGetAbility(LibraryFixtures::loader(), $this->design());
@@ -162,9 +162,9 @@ final class DiviReadAbilitiesTest extends TestCase
 
         $denied = new DiviNodeGetAbility(LibraryFixtures::loader(LibraryFixtures::access(['divi_library'])), $this->design());
         $refusal = $denied->permission(['post_id' => 1057, 'id' => 'm0']);
-        self::assertToolError($refusal, 'forbidden');
+        self::assertToolError($refusal, 'not_found');
         self::assertStringNotContainsString('Geheim', $refusal->get_error_message());
         $outline = new DiviOutlineAbility(LibraryFixtures::loader(LibraryFixtures::access(['divi_library'])), $this->design());
-        self::assertToolError($outline->execute(['post_id' => 1057]), 'forbidden');
+        self::assertToolError($outline->execute(['post_id' => 1057]), 'not_found');
     }
 }