請說明爲什麼下面的測試失敗

Question

下面的方法適當地通過測試：

def associate_grid_location 
     devices.each do |device| 
      if device.grid_location and grid_location_id.nil? 
       update_attribute(:grid_location_name,device.grid_location.grid_name) 
       update_attribute(:grid_location_id,device.grid_location_id) 
       break 
      end 
     end 
    end 

但是，如果我運行這個方法的調用相同的測試邏輯，它沒有更新每個櫃grid_location_name和grid_location_id ：

def self.associate_grid_locations 
     Cabinet.all.each do |cabinet| 
      cabinet.associate_grid_location 
     end 
    end 

請提出爲什麼它可能會失敗。

通過測試：

test "Cabinet associate grid location from device where device has grid location" do 
    @cabinet = cabinets(:one) 
    @cabinet.grid_location_id = nil 
    @device = devices(:one) 
    @grid_location = grid_locations(:one) 
    @grid_location.grid_name = "test location" 
    @device.grid_location = @grid_location 
    @cabinet.devices << @device 
    @cabinet.associate_grid_location 

    assert_equal @grid_location.grid_name, @cabinet.grid_location_name, "Failed: Did not update cabinet grid location" 
    assert_equal @device.grid_location.id, @cabinet.grid_location_id, "Failed: Did not update cabinet grid location" 
    end 

失敗的測試：

test "Cabinet associate grid location from device where device has grid location (Called on Cabinet)" do 
    @cabinet = cabinets(:one) 
    @cabinet.grid_location_id = nil 
    @device = devices(:one) 
    @grid_location = grid_locations(:one) 
    @grid_location.grid_name = "test location" 
    @device.grid_location = @grid_location 
    @cabinet.devices << @device 
    Cabinet.associate_grid_locations 

    assert_equal @grid_location.grid_name, @cabinet.grid_location_name, "Failed: Did not update cabinet grid location" 
    assert_equal @device.grid_location.id, @cabinet.grid_location_id, "Failed: Did not update cabinet grid location" 
    end 

謝謝。

Answer 1

Cabinet.associate_grid_locations調用Cabinet.all，它會實例化新對象（除非啓用了身份映射），這些對象不會鏈接到您在測試中實例化的對象。假設沒有其他錯誤，在@cabinet上調用#reload應該使測試通過。