Laravel：如何从中间表获取记录？

我正在使用Lumen 5.1版本，我在任务和用户之间有一个多对多的关系。

任务模型

public function user()
{
    return $this->belongsToMany('App\Models\Auth\User', 'task_user');
}
public function domain()
{
    return $this->hasOne('App\Models\Domain', 'domain_id');
}

用户模型

public function tasks()
{
    return $this->belongsToMany(Task::class, 'task_user');
}

UserTask模型

class UserTask {}

我想要查询任务的用户，我的代码是

$tasks = Task::Where(function ($query) use ($domainId) {
    $query->where("domain_id", $domainId)
        ->where("is_done", 0)
        ->orwherehas('tasks.user.id', \Auth::id)
        ->orderBy('due_date', 'DESC');
})
->orWhere(function ($query) use ($domainId) {
    $query->where("domain_id", $domainId)
        ->Where("is_done", 1)
        ->Where("closed_dated", Carbon::today())
        ->orwherehas('tasks.user.id', \Auth::id)
        ->orderBy('closed_date', 'ASC');
})
->get();

我的问题是whereHas是否正确？tasks.user.id是否正确？我可以通过这种方式获取用户的id吗？因为这个问题我这样做的。

技术主管告诉我我的代码是错误的，他会使用where，他说当你想要运行一个闭包时才使用whereHas。

迁移：

任务表

public function up()
{
    Schema::create($this->getTable(), function (Blueprint $table) {
        $table->increments('id');
        $table->string('title')->nullable();
        $table->dateTime('submit_date');
        $table->dateTime('closed_date');
        $table->dateTime('due_date');
        $table->tinyInteger('is_done')->default(0);
        $table->integer('domain_id')->unsigned()->nullable();
        $table->foreign('domain_id')->references('id')
            ->on(self::getTableName('domains'))->onDelete('cascade');
        $table->bigInteger('created_by')->unsigned()->nullable();
        $table->foreign('created_by')->references('id')
            ->on(self::getTableName('auth_users', false))->onDelete('cascade');
        $table->bigInteger('closed_by')->unsigned()->nullable();
        $table->foreign('closed_by')->references('id')
            ->on(self::getTableName('auth_users', false))->onDelete('cascade');
        $table->timestamps();
    });
}
public function down()
{
    Schema::drop($this->getTable());
}

任务用户表

public function up()
{
    Schema::create($this->getTable(), function (Blueprint $table) {
        $table->increments('id');
        $table->integer('task_id')->unsigned()->nullable();
        $table->foreign('task_id')->references('id')
            ->on(self::getTableName('tasks'))
            ->onDelete('cascade');
        $table->bigInteger('user_id')->unsigned()->nullable();
        $table->foreign('user_id')->references('id')
            ->on(self::getTableName('auth_users', false))
            ->onDelete('cascade');
    });
}
public function down()
{
    Schema::drop($this->getTable());
}