Laravel JsonResource: array_merge_recursive(): Argument #2 is not an array - laravel

Question

I have a JsonResource of Post that should return a single post. But after joining some other data I get this error: array_merge_recursive(): Argument #2 is not an array.
This does not work:
/**
* Display the specified resource.
*
* #param int $id
* #return \Illuminate\Http\Response
*/
public function show($slug)
{
// $post = Post::findOrFail($id);
$post = Post::where('slug', $slug)->first();
// return single post as resource
return new PostResource($post);
}
When I directly return $posts, I get a json back, almost fine. But it doesnt contain the joined data comment.
Here is the class Post extends JsonResource.
public function toArray($request)
{
// return parent::toArray($request);
$img = '.'.pathinfo('storage/'.$this->image, PATHINFO_EXTENSION);
$imgName = str_replace($img,'', $this->image);
$img = $imgName.'-cropped'.$img;
return [
'id' => $this->id,
'title' => $this->title,
'body' => $this->body,
'excerpt' => $this->excerpt,
'image' => asset('/storage/' . $this->image),
'image_small' => asset('storage/' . $img),
'author_id' => $this->author_id,
'category_id' => $this->category_id,
'seo_title' => $this->seo_title,
'slug' => $this->slug,
'meta_description' => $this->meta_description,
'meta_keywords' => $this->meta_keywords,
'status' => $this->status,
'featured' => $this->featured,
'created_at' => $this->created_at,
'updated_at' => $this->updated_at,
'user' => User::find($this->author_id),
'commentCount' => $this->comment->where(['status' => 1, 'id_post' => $this->id])->count(),
];
}
// **Big mistake below here**:
public function with($request)
{
// return [
// 'version' => '1.0.0',
// ];
}
Model:
class Post extends Model
{
public $primary_key = 'id';
public $foreign_key = 'id_post';
public function user()
{
return $this->belongsTo('App\User', 'id_author', 'id');
}
public function comment()
{
return $this->belongsTo('App\Comment', 'id', 'id_post');
}
}
Why do I get a warning about array_merge_recursive()?

Answer 1

I wan't reproduce issue with your code, but - are you sure you included everything? Looking at https://laravel.com/docs/5.6/eloquent-resources#writing-resources it's possible to define additional data data will be returned too like this:
/**
* Get additional data that should be returned with the resource array.
*
* #param \Illuminate\Http\Request $request
* #return array
*/
public function with($request)
{
return [
'meta' => [
'key' => 'value',
],
];
}
So I was able to reproduce the issue when I added to this Post resource class the following method:
public function with($request)
{
return 'test';
}
as you see it's returning just string and not array and then I was getting same error as you did.
But when I didn't have this method implemented at all or when I return just an array, everything is fine.
So to sum up - make sure you don't have with method defined that returns something else than array.