How to properly type hint custom BaseModel so IDE recognizes child model class instead of BaseModel?

[mrvipchien]

I have a custom BaseModel that extends Illuminate\Database\Eloquent\Model, and I want PHPStorm (and other IDEs) to correctly recognize the return type of Eloquent methods when called on child models.

Current issue:
When I write: $post = Post::query()->first();

The IDE thinks $post is an instance of BaseModel instead of Post.

My current code:

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;

class BaseModel extends Model
{
    use HasFactory;
}

And my child model:

class Post extends BaseModel
{
    // ... model implementation
}

Expected:
I want the IDE to recognize that:

• Post::query() returns Builder<Post>

• Post::first() returns Post|null

• Post::find($id) returns Post|null

• etc.

[SamHambunan]

So i think one way to properly tell the IDE :

is to use the @template annotation we can just think of it as like a subclass of your BaseModel. For example in your case it would be the Post model we can define it by:

/**
 * @template TModel of \App\Models\BaseModel
 * @mixin Builder<TModel>
 */
class BaseModel extends Model

dont mind the @mixin annotation ill explain it later
now you can override the find method or any other methods that returns your subClass e.g Post in your case by doing this:

 /**
    * @param mixed $id
     * @return static|null
     */
    public static function find($id, $columns = ['*'])
    {
        return parent::find($id, $columns);
    }

now the IDE that you are using knows that you are returning its subclass because in this annotation: @template TModel of \App\Models\BaseModel tells that methods that returns the instance of itself / static should return the instance of the TModel or the child model so now instead of return BaseModel the IDE now knows that it returns Post model instead.

now in this annotation * @mixin Builder<TModel> this just simply says that every method that returns a Builder object are now specific to the child model which is what we want in this case now it will be Builder<Post> now you can override builder methods by this:

  /**
     *
     * @return \Illuminate\Database\Eloquent\Builder<static>
     */
 public static function query(): Builder
    {
        return parent::query();
    }

now the IDE will know that it returns a Builder specific to the caller or the subclass that is in your case Post so i think thats it hope it helps :)

[shaedrich]

this annotation * @mixin Builder<TModel> this just simply says that every method that returns a Builder object are now specific to the child model

This is not entirely correct. This applies to methods that are delegated to the underlying Builder class via the __call() magic method on the Model class