Django模型中的Python factory_boy库m2m？

Question

我目前正在使用factory_boy我的测试中创建灯具. Factory_boydocs仅提到了SubFactory哪些可能就像ForeignKey模型中的字段一样.但是,ManyToMany协会没有任何内容.如果我有一个以下Post模型,我将如何为它创建一个工厂？

class Post(models.Model):
    title = models.CharField(max_length=100)
    tags = models.ManyToManyField('tags.Tag')

class PostFactory(factory.Factory):
    FACTORY_FOR = Post

    title = 'My title'
    tags = ???

Answer 1

怎么样post_generation钩子 - 我假设你使用较新版本的factory_boy？

import random
import factory

class PostFactory(factory.Factory):
    FACTORY_FOR = Post
    title = factory.Sequence(lambda n: "This is test title number" + n)
    @factory.post_generation(extract_prefix='tags')
    def add_tags(self, create, extracted, **kwargs):
        # allow something like PostFactory(tags = Tag.objects.filter())
        if extracted and type(extracted) == type(Tag.objects.all()):
            self.tags = extracted
            self.save()
        else:
            if Tag.objects.all().count() < 5:
                TagFactory.create_batch(5, **kwargs)
            for tag in Tag.objects.all().order_by('?')[:random.randint(1, 5)]:
                self.tags.add(tag)

请注意,您可以使用PostFactory(tags__field = 'some fancy default text'),但我建议TagFactory使用序列创建好...

你应该能够绑定PostFactory(tags = Tag.objects.filter())但是这部分没有经过测试......

Answer 2

您可以覆盖_prepareclassmethod:

class PostFactory(Factory):
    FACTORY_FOR = Post

    title = 'My title'

    @classmethod
    def _prepare(cls, create, **kwargs):
        post = super(PostFactory, cls)._prepare(create, **kwargs)
        if post.id:
            post.tags = Tag.objects.all()
        return post

请注意,如果帖子没有ID,则无法为帖子添加标签.

Answer 3

我没有测试过，但是问题出在哪里：

class PostFactory(factory.Factory):
    FACTORY_FOR = Post
    title = 'My title'

class TagFactory(factory.Factory):
    FACTORY_FOR = Tag

post = PostFactory()
tag = TagFactory()
post.tags.add(tag)