2.x

app/Actions/Projects/AddUser.php

@@ -0,0 +1,33 @@
+<?php
+
+namespace App\Actions\Projects;
+
+use App\Models\Project;
+use App\Models\User;
+use Illuminate\Database\Query\Builder;
+use Illuminate\Validation\Rule;
+
+class AddUser
+{
+    public function add(Project $project, array $input): void
+    {
+        /** @var User $user */
+        $user = User::query()->findOrFail($input['user']);
+
+        $project->users()->detach($user);
+        $project->users()->attach($user);
+    }
+
+    public static function rules(Project $project): array
+    {
+        return [
+            'user' => [
+                'required',
+                Rule::exists('users', 'id'),
+                Rule::unique('user_project', 'user_id')->where(function (Builder $query) use ($project) {
+                    $query->where('project_id', $project->id);
+                }),
+            ],
+        ];
+    }
+}