没有失败时，Excel 上传显示错误

如何解决没有失败时，Excel 上传显示错误

我使用 Laravel-5.8 和 Maatwebsite-3.1 从 Excel 导入数据库：

控制器：

public function importGrade(Request $request){        
        if (empty($request->file('file'))) 
        {
            return back()->with('error','File cannot be empty!');
        }
        else{   
            request()->validate([
                'file'  => 'required|mimes:xls,xlsx,csv|max:2048',]);

            $pathTofile = $request->file('file')->store('import');
            $import =  new GradeLevelsImport;
            $import->import($pathTofile); 

                if($import->failures()->isNotEmpty()){
                    $failures = $import->failures();
                    return view('hr.grades.import_grade_form')->with('failures',$failures);
                }
            Session::flash('success','Records Imported Successfully');
            return redirect()->route('hr.grades.index'); 
        }

Excel 导入：

class GradeLevelsImport implements
  ToModel,WithBatchInserts,WithHeadingRow,SkipsOnError,WithValidation,SkipsOnFailure
{
use Importable,SkipsErrors,SkipsFailures;

public function model(array $row)
{ 
    return new HrGrade([
        'grade_level_code'                  => $row['grade_code'] ?? '','grade_level_name'                  => $row['grade_name'] ?? '','company_id'                        => Auth::user()->company_id,'created_by'                        => Auth::user()->id,'created_at'                        => date("Y-m-d H:i:s"),'is_active'                         => 1,]);       
 }
}

这是 Flash 会话视图：

查看刀片

@if (count($failures) >= 1)
<div class="alert alert-danger alert-block" role="alert">
  <button type="button" class="close" data-dismiss="alert">×</button>
  <strong>Failed Upload(s): </strong>
  <table class=" table table-bordered table-striped table-hover">
    <thead>
      <tr>
        <th>
          Row
        </th>
        <th>
          Attribute
        </th>
        <th>
          Error
        </th>
        <th>
          Values
        </th>
      </tr>
    </thead>
    <tbody>
      @foreach( $failures as $validation )
      <tr>
        <td>
          {{ $validation->row() ?? '' }}
        </td>
        <td>
          {{ $validation->attribute() ?? '' }}
        </td>
        <td>
          <ul>
            @foreach($validation->errors() as $e)
            <li>{{$e ?? '' }}</li>
            @endforeach
          </ul>
        </td>
        <td>
          <ul>
            @foreach($validation->values() as $v)
            <li>{{$v ?? '' }}</li>
            @endforeach
          </ul>
        </td>
      </tr>
      @endforeach
    </tbody>
  </table>
</div>
@endif

如果有故障，一切正常。它显示失败并上传成功的。

但问题在于没有失败并且一切正常。它显示此错误：

production.ERROR：未定义变量：失败

它指向这条线

@if (count($failures) >= 1)

同一行代码在出现故障的地方还可以。

如何解决这个问题？

谢谢