Gate errors on Laravel 5.5 - php

Question

I'm following a tutorial about Authorization in laravel, but it seems it got some errors in the code like this:
"Type error: Argument 2 passed to App\Providers\AuthServiceProvider::App\Providers\{closure}() must be an instance of App\Providers\Post, instance of App\Post given, called in E:\xampp\htdocs\cms\vendor\laravel\framework\src\Illuminate\Auth\Access\Gate.php on line 323 ◀"
I got those error code when I'm accessing http://cms.dev/posts/edit/2. here's the code that i've put on AuthServicesProfider:
public function registerPostPolicies()
{
Gate::define('create-post', function ($user) {
return $user->hasAccess(['create-post']);
});
Gate::define('update-post', function ($user, Post $post) {
return $user->hasAccess(['update-post']) or $user->id == $post->user_id;
});
Gate::define('publish-post', function ($user) {
return $user->hasAccess(['publish-post']);
});
Gate::define('see-all-drafts', function ($user) {
return $user->inRole('editor');
});
}
and here's the code for the update.blade:
#extends('layouts.app')
#section('content')
<div class="container">
<div class="row">
<div class="col-md-8 col-md-offset-2">
<div class="panel panel-default">
<div class="panel-heading">Update Post</div>
<div class="panel-body">
<form class="form-horizontal" role="form" method="POST" action="{{ route('update_post', ['post' => $post->id]) }}">
{{ csrf_field() }}
<div class="form-group{{ $errors->has('title') ? ' has-error' : '' }}">
<label for="title" class="col-md-4 control-label">Title</label>
<div class="col-md-6">
<input id="title" type="text" class="form-control" name="title" value="{{ old('title', $post->title) }}" required autofocus>
#if ($errors->has('title'))
<span class="help-block">
<strong>{{ $errors->first('title') }}</strong>
</span>
#endif
</div>
</div>
<div class="form-group{{ $errors->has('body') ? ' has-error' : '' }}">
<label for="body" class="col-md-4 control-label">Body</label>
<div class="col-md-6">
<textarea name="body" id="body" cols="30" rows="10" class="form-control" required>{{ old('body', $post->body) }}</textarea>
#if ($errors->has('body'))
<span class="help-block">
<strong>{{ $errors->first('body') }}</strong>
</span>
#endif
</div>
</div>
<div class="form-group">
<div class="col-md-6 col-md-offset-4">
<button type="submit" class="btn btn-primary">
Update
</button>
#can('publish-post')
<a href="{{ route('publish_post', ['post' => $post->id]) }}" class="btn btn-primary">
Publish
</a>
#endcan
<a href="{{ route('list_posts') }}" class="btn btn-primary">
Cancel
</a>
</div>
</div>
</form>
</div>
</div>
</div>
</div>
</div>
#endsection
I really have no idea about how to fix it since i really don't understand about authorization in Laravel. Thanks.

Answer 1

You're missing a use statement for the Post class, therefore PHP assumes the gate takes the Post class from the current namespace, hence the App\Providers\Post in the error message.
Add the following in the provider class:
use App\Post;