单元测试 Django 模型保存功能

Question

我正在创建测试以检查自定义校准模型保存功能是否更新资产记录（外键），如果它是资产的最新校准记录。save 函数在实时开发和生产服务器中甚至在 django shell 中都完全按预期执行，但在测试期间似乎失败了...

模型.py

class Asset(models.Model):
    ...
    requires_calibration = models.BooleanField()
    passed_calibration = models.BooleanField(default=False)
    calibration_date_prev = models.DateField(null=True, blank=True)
    calibration_date_next = models.DateField(null=True, blank=True)


class CalibrationRecord(models.Model):
    calibration_record_id = models.AutoField(primary_key=True)
    asset = models.ForeignKey(
                              "myapp.Asset",
                              on_delete=models.CASCADE,
                              limit_choices_to={"requires_calibration": True}
                              )
    calibration_date = models.DateField(default=timezone.now)
    calibration_date_next = models.DateField(null=True, blank=True)
    calibration_outcome = models.CharField(max_length=10, default="Pass")

    def save(self, *args, **kwargs):

        super(CalibrationRecord, self).save(*args, **kwargs)

        # Check if this is the latest calibration record for any asset, if so update asset.calibration_dates and status
        latest_asset_calibration = CalibrationRecord.objects.filter(asset=self.asset.pk).order_by(
            "-calibration_date", "-calibration_record_id")[0]

        if self.pk == latest_asset_calibration.pk:

            Asset.objects.filter(pk=self.asset.pk).update(calibration_date_prev=self.calibration_date)

            if self.calibration_date_next:
                Asset.objects.filter(pk=self.asset.pk).update(calibration_date_next=self.calibration_date_next)
            else:
                Asset.objects.filter(pk=self.asset.pk).update(calibration_date_next=None)

            if self.calibration_outcome == "Pass":
                Asset.objects.filter(pk=self.asset.pk).update(passed_calibration=True)
            else:
                Asset.objects.filter(pk=self.asset.pk).update(passed_calibration=False)

tests_models.py 示例失败测试

class CalibrationRecordTests(TestCase):
    def test_calibration_record_updates_asset_cal_date_prev(self):
        """
        All calibration records should update related Asset record's "calibration_date_prev" to calibration_date
        """
        asset1 = Asset.objects.create(asset_description="Test Asset 2", requires_calibration=True)
        self.assertIsNone(asset1.calibration_date_prev)
        cal = CalibrationRecord.objects.create(asset=asset1, calibration_description="Test Calibration 2", calibration_date=timezone.now())
        self.assertEqual(cal.calibration_date, asset1.calibration_date_prev)

错误日志

======================================================================
FAIL: test_calibration_record_updates_asset_cal_date_prev (assetregister.tests_models.CalibrationRecordTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "C:\[path]\app\tests_models.py", line 159, in test_calibration_record_updates_asset_cal_date_prev
self.assertEqual(cal.calibration_date, asset1.calibration_date_prev)
AssertionError: datetime.datetime(2018, 2, 26, 12, 26, 34, 457513, tzinfo=<UTC>) != None
======================================================================

我所有与此自定义校准记录保存功能相关的测试似乎都失败了，因为相关的资产记录没有在应有的时候更新。

任何想法为什么这会在开发和生产期间起作用但在测试期间不起作用？

尽管 .create() 方法应该在之后自动执行 .save() ，但我什至尝试在创建校准记录后手动执行 .save() ，但它似乎仍然失败。

Answer 1

解决了！

自定义保存功能正确更新数据库，但不是正在测试的模型实例！需要通过使用类似的方法再次调用它来刷新模型实例以获取任何更新[model].objects.get()

例如：

    asset = Asset.objects.create(asset_description="Test Asset 2", requires_calibration=True)
    self.assertIsNone(asset.calibration_date_prev)
    CalibrationRecord.objects.create(asset=asset, calibration_description="Test Calibration 2",
                                     calibration_date=timezone.now())
    cal = CalibrationRecord.objects.get(calibration_description="Test Calibration 2")
    asset = Asset.objects.get(asset_description="Test Asset 2")
    self.assertEqual(cal.calibration_date, asset.calibration_date_prev)