Ainda é simples

Usar um framework como o Laravel significa que o projeto está automaticamente seguro… Né?

<?php
// Arquivo: app/Http/Requests/TestRequest.php

namespace App\Http\Requests;

use App\Models\Post;
use Illuminate\Foundation\Http\FormRequest;
use Illuminate\Validation\Rule;

class TestRequest extends FormRequest
{
    public function rules(): array
    {
        return [
            'slug' => [
                'required',
                'string',
                'max:64',
                'alpha_dash:ascii',
                Rule::unique(Post::class),
            ],
            'title' => [
                'required',
                'string',
                'max:128',
            ],
            'content' => [
                'required',
                'string',
                'max:65536',
            ],
        ];
    }
}

<?php
// Arquivo: app/Http/Controllers/TestController.php

namespace App\Http\Controllers;

use App\Http\Requests\TestRequest;
use App\Models\Post;
use Illuminate\Http\Request;
use Illuminate\Http\Response;
use Illuminate\Routing\Controller;

class TestController extends Controller
{
    public function get(Request $request, string $slug): Response
    {
        $post = Post::where('slug', $slug)
            ->userCanRead($request->user()->id)
            ->select([
                'title',
                'content',
            ])
            ->firstOrFail();

        return response()->view('test', [
            'post' => $post,
        ]);
    }

    public function post(TestRequest $request): Response
    {
        Post::create([
            'slug' => $request->slug,
            'title' => $request->title,
            'content' => $request->content,
            'author_id' => $request->user()->id,
        ]);

        return response()->noContent();
    }
}

<!-- Arquivo: resources/views/test.blade.php -->
<!DOCTYPE html>
<html lang="pt-BR">

<head>
    <title>{{ $post->title }} | TestSite</title>

    <meta charset="utf-8">
</head>

<body>
    <main>
        <h1>{{ $post->title }}</h1>
        <div>{{ $post->content }}</div>
    </main>
</body>

</html>