fix(tiktok): send an empty JSON object to creator_info (#224)

Laravel serialises the empty array argument to `[]`. TikTok's
creator_info endpoint expects an object and rejects the array with
invalid_params, so every query failed and the service returned
emptyPayload(), leaving the composer with no creator data.

Co-authored-by: Paulo Castellano <paulo@castellanos.llc>

app/Services/Social/TikTokCreatorInfo.php

@@ -65,7 +65,8 @@ private function fetchFresh(SocialAccount $account): array
         $this->accessToken = $account->access_token;
 
         $response = $this->getHttpClient()
-            ->post("{$this->baseUrl}/post/publish/creator_info/query/", []);
+            ->withBody('{}', 'application/json; charset=UTF-8')
+            ->post("{$this->baseUrl}/post/publish/creator_info/query/");
 
         if ($response->failed()) {
             Log::warning('TikTok creator_info query failed', [

tests/Feature/Services/Social/TikTokCreatorInfoTest.php

@@ -49,6 +49,18 @@
         ->and($info['max_video_post_duration_sec'])->toBe(600);
 });
 
+test('it sends an empty json object as the request body', function () {
+    Http::fake([
+        $this->api.'/post/publish/creator_info/query/' => Http::response(['data' => []], 200),
+    ]);
+
+    $this->service->fetch($this->account);
+
+    Http::assertSent(function ($request) {
+        return $request->body() === '{}';
+    });
+});
+
 test('it returns an empty payload when the api fails', function () {
     Http::fake([
         $this->api.'/post/publish/creator_info/query/' => Http::response(['error' => 'unauthorized'], 401),