工厂男孩：定义依赖于其他领域的领域

Question

如何使用 factory-boy 定义依赖于其他字段的字段？

例如，我想定义一个 email，它依赖于 User 的 first name 和 last name。

我尝试使用 post_generation 装饰器。但是，我的系统需要在创建实例之前定义电子邮件。

Answer 1

from the docs:

The LazyAttribute is a simple yet extremely powerful building brick for extending a Factory.

It takes as argument a method to call (usually a lambda); that method should accept the object being built as sole argument, and return a value.

class UserFactory(factory.Factory):
    class Meta:
        model = User

    username = 'john'
    email = factory.LazyAttribute(lambda o: '%s@example.com' % o.username)

或 lazy_attribute 装饰器。

from the docs:

If a simple lambda isn’t enough, you may use the lazy_attribute() decorator instead.

This decorates an instance method that should take a single argument, self; the name of the method will be used as the name of the attribute to fill with the return value of the method:

class UserFactory(factory.Factory)
    class Meta:
        model = User

    name = u"Jean"

    @factory.lazy_attribute
    def email(self):
        # Convert to plain ascii text
        clean_name = (unicodedata.normalize('NFKD', self.name)
                        .encode('ascii', 'ignore')
                        .decode('utf8'))
        return u'%s@example.com' % clean_name

Answer 2

您还可以对依赖于其他字段的字段使用 factory.SelfAttribute。

在你的情况下，LazyAttribute 工作正常，而且很清楚，但如果你需要做一些更复杂的事情，SelfAttribute 它会是一个更好的选择。

例如，假设我们有一个名为 Course 的实体，具有 start_date 和 end_date。每门课程都有期末考试，必须在课程开始后和课程结束前参加。那么，model.py 应该是这样的：

class Course(models.Model):
    start_date = models.DateTimeField(auto_now_add=False, blank=False)
    end_date = models.DateTimeField(auto_now_add=False, blank=False)

class Test(models.Model):
    course = models.ForeignKey(
        to=Course, blank=False, null=False, on_delete=models.CASCADE
    )
    date = models.DateField()

现在，让我们创建我们的 factory.py:

class CourseFactory(DjangoModelFactory):
    class Meta:
        model = Course

    start_date = factory.Faker(
        "date_time_this_month", before_now=True, after_now=False, tzinfo=pytz.UTC
    )
    end_date = factory.Faker(
        "date_time_this_month", before_now=False, after_now=True, tzinfo=pytz.UTC
    )

class TestFactory(DjangoModelFactory):
    class Meta:
        model = Test

    date = factory.Faker(
        "date_between_dates",
        date_start=factory.SelfAttribute('..course.start_date'),
        date_end=factory.SelfAttribute('..course.end_date')
    )
    course = factory.SubFactory(CourseFactory)

正如您在 TestFactory 中看到的，我们可以引用正在构造的对象的另一个字段或其属性。

工厂男孩：定义依赖于其他领域的领域

factory boy: define field that depends on other field

django

django-testing

django-tests

factory-boy

from the docs:

from the docs: