筛选自己的话题为什么不用模型关联，使用 user_id 筛选呢？

1、筛选自己的话题应该是模型关联查询，
2、根据测试方法名称，这里要做的应该是通过任意用户名筛选文章，并非筛选自己的文章。

public function a_user_can_filter_threads_by_any_username()
{
    $this->signIn(create('App\User',['name' => 'NoNo1']));

    $threadByNoNo1 = create('App\Thread',['user_id' => auth()->id()]);
    $threadNotByNoNo1 = create('App\Thread');

    $this->get('threads?by=NoNo1')
        ->assertSee($threadByNoNo1->title)
        ->assertDontSee($threadNotByNoNo1->title);
}

控制器方法也是根据任意用户名查询用户文章（非授权下）

public function index(Channel $channel)
{
    if($channel->exists){
        $threads = $channel->threads()->latest();
    }else{
        $threads = Thread::latest();
    }

    if($username = request('by')){
        $user = \App\User::where('name',$username)->firstOrFail();

        $threads->where('user_id',$user->id);
    }

    $threads  = $threads->get();

    return view('threads.index',compact('threads'));
}

所以这里的测试方法是不是应该改成：

public function a_user_can_filter_threads_by_any_username()
{
    $user = factory('App\User')->create(['name' => 'NoNo1']);

    $threadByNoNo1 = create('App\Thread',['user_id' => $user->id]);
    $threadNotByNoNo1 = create('App\Thread');

    $this->get('threads?by=NoNo1')
        ->assertSee($threadByNoNo1->title)
        ->assertDontSee($threadNotByNoNo1->title);
}