How can test a resource collection structure?

[Nothehi]

Sometimes we need to write a unit test for collections, There are some methods for testing JSON structure in feature test, but in the unit test there is no way to test structures! of course, some assertions exist for checking keys but that is not what I want. I need a method like the assertJsonStructure to do.

Example

assume that we have a resource collection like this:

ExampleResource

<?php

namespace App\Http\Resources;

use Illuminate\Http\Resources\Json\JsonResource;

class ExampleResource extends JsonResource
{
    /**
     * Transform the resource into an array.
     *
     * @param  \Illuminate\Http\Request  $request
     * @return array|\Illuminate\Contracts\Support\Arrayable|\JsonSerializable
     */
    public function toArray($request)
    {
        return [
            'first_field' => $this->first_field,
            'second_field' => SecondExampleResource::collection($this->second_field),
        ];
    }
}

SecondExampleResource

<?php

namespace App\Http\Resources;

use Illuminate\Http\Resources\Json\JsonResource;

class SecondExampleResource extends JsonResource
{
    /**
     * Transform the resource into an array.
     *
     * @param  \Illuminate\Http\Request  $request
     * @return array|\Illuminate\Contracts\Support\Arrayable|\JsonSerializable
     */
    public function toArray($request)
    {
        return [
            'foo' => $this->foo,
            'bar' => $this->bar,
        ];
    }
}

now I want to test when I make a collection from ExampleResource that the keys will be something like this:

$example = ExampleResource::collection(Example::all());

assertJsonStructure($example, [
    '*' => [
        'first_field',
        'second_field' => [
            '*' => [
                'foo', 'bar'
            ]
        ]
    ]
]);

It would be highly appreciated if anyone can advise me!