fix(posts): return empty Eloquent collection for posts without category

app/Services/WpPostService.php

@@ -120,7 +120,9 @@ public static function getRelatedPosts(WpPost $post, int $limit = 3): Collection
                 ?->slug;
 
             if (! $categorySlug) {
-                return collect();
+                // collect() builds a Support\Collection, which is not an
+                // Eloquent\Collection and fails this method's return type.
+                return new Collection;
             }
 
             return WpPost::query()

phpunit.xml

@@ -22,7 +22,8 @@
         <env name="APP_MAINTENANCE_DRIVER" value="file"/>
         <env name="BCRYPT_ROUNDS" value="4"/>
         <env name="CACHE_STORE" value="array"/>
-        <env name="DB_DATABASE" value="testing"/>
+        <env name="DB_CONNECTION" value="sqlite"/>
+        <env name="DB_DATABASE" value=":memory:"/>
         <env name="MAIL_MAILER" value="array"/>
         <env name="PULSE_ENABLED" value="false"/>
         <env name="QUEUE_CONNECTION" value="sync"/>

resources/js/components/PostCard.vue

@@ -39,7 +39,11 @@ const getFormattedDate = (post: Post) => {
                     decoding="async"
                 />
             </Link>
-            <Link :href="'/category/' + post.categories[0].slug" class="absolute bottom-0 left-[5px] bg-[#e6c619] px-2 py-1 text-black">
+            <Link
+                v-if="post.categories?.length"
+                :href="'/category/' + post.categories[0].slug"
+                class="absolute bottom-0 left-[5px] bg-[#e6c619] px-2 py-1 text-black"
+            >
                 {{ post.categories[0].name }}
             </Link>
         </div>

resources/js/components/PostContentCover.vue

@@ -28,6 +28,7 @@ const { coverData } = defineProps<{
             <div class="relative mx-auto w-full border-b-3 border-black xl:w-[970px]">
                 <img class="w-full xl:h-[530px]" :src="coverData.thumbnail" :alt="'Capa do post - ' + coverData.title" />
                 <Link
+                    v-if="coverData.categories?.length"
                     :href="'/category/' + coverData.categories[0].slug"
                     class="absolute bottom-0 left-[20px] bg-[#e6c619] px-2 py-1 font-bold text-black"
                 >

tests/Feature/RelatedPostsTest.php

@@ -0,0 +1,103 @@
+<?php
+
+use App\Models\WpPost;
+use App\Services\WpPostService;
+use Illuminate\Database\Eloquent\Collection;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\DB;
+use Illuminate\Support\Facades\Schema;
+
+beforeEach(function () {
+    // Minimal slice of the WordPress schema getRelatedPosts() touches.
+    // A reusable fixture set comes with the test infrastructure PR.
+    Schema::create('wp_posts', function (Blueprint $table) {
+        $table->id('ID');
+        $table->unsignedBigInteger('post_author')->default(0);
+        $table->string('post_title');
+        $table->text('post_excerpt')->nullable();
+        $table->text('post_content')->nullable();
+        $table->string('post_name');
+        $table->string('post_type')->default('post');
+        $table->string('post_status')->default('publish');
+        $table->dateTime('post_date');
+        $table->string('guid')->default('');
+    });
+
+    Schema::create('wp_postmeta', function (Blueprint $table) {
+        $table->id('meta_id');
+        $table->unsignedBigInteger('post_id');
+        $table->string('meta_key');
+        $table->text('meta_value');
+    });
+
+    Schema::create('wp_terms', function (Blueprint $table) {
+        $table->id('term_id');
+        $table->string('name');
+        $table->string('slug');
+    });
+
+    Schema::create('wp_term_taxonomy', function (Blueprint $table) {
+        $table->id('term_taxonomy_id');
+        $table->unsignedBigInteger('term_id');
+        $table->string('taxonomy');
+    });
+
+    Schema::create('wp_term_relationships', function (Blueprint $table) {
+        $table->unsignedBigInteger('object_id');
+        $table->unsignedBigInteger('term_taxonomy_id');
+    });
+
+    cache()->flush();
+});
+
+function insertPost(int $id, string $slug): WpPost
+{
+    DB::table('wp_posts')->insert([
+        'ID' => $id,
+        'post_author' => 1,
+        'post_title' => "Post {$id}",
+        'post_name' => $slug,
+        'post_type' => 'post',
+        'post_status' => 'publish',
+        'post_date' => '2026-07-01 10:00:00',
+    ]);
+
+    return WpPost::query()->findOrFail($id);
+}
+
+function attachCategory(int $postId, string $slug): void
+{
+    $termId = DB::table('wp_terms')->insertGetId(['name' => ucfirst($slug), 'slug' => $slug]);
+    $ttId = DB::table('wp_term_taxonomy')->insertGetId(['term_id' => $termId, 'taxonomy' => 'category']);
+    DB::table('wp_term_relationships')->insert(['object_id' => $postId, 'term_taxonomy_id' => $ttId]);
+}
+
+it('returns an Eloquent collection when the post has no category', function () {
+    $post = insertPost(1, 'sem-categoria');
+
+    $related = WpPostService::getRelatedPosts($post);
+
+    // The regression: collect() returns Support\Collection and blows up the
+    // declared Eloquent\Collection return type with a TypeError.
+    expect($related)->toBeInstanceOf(Collection::class)
+        ->and($related)->toBeEmpty();
+});
+
+it('still returns posts from the same category', function () {
+    $post = insertPost(1, 'principal');
+    attachCategory(1, 'games');
+
+    $sibling = insertPost(2, 'irmao');
+    DB::table('wp_term_relationships')->insert([
+        'object_id' => 2,
+        'term_taxonomy_id' => DB::table('wp_term_taxonomy')->value('term_taxonomy_id'),
+    ]);
+
+    $related = WpPostService::getRelatedPosts($post);
+
+    expect($related)->toBeInstanceOf(Collection::class)
+        ->and($related->pluck('ID')->all())->toBe([2])
+        ->and($related->pluck('ID')->all())->not->toContain(1);
+
+    unset($sibling);
+});