Factory Boy 随机选择带有字段选项的字段 "choices"

Question

当 Django 模型中的字段具有选项选项时，请参阅 Django choices field option，它利用包含 2 个项目的可迭代对象的可迭代对象来定义允许哪些值。例如：

型号

class IceCreamProduct(models.Model):
    PRODUCT_TYPES = (
        (0, 'Soft Ice Cream'),
        (1, 'Hard Ice Cream'),
        (2, 'Light Ice Cream'),
        (3, 'French Ice Cream'),
        (4, 'Italian-style Gelato'),
        (5, 'Frozen Dairy Dessert'),
    )
    type = models.PositiveSmallIntegerField('Type', choices=PRODUCT_TYPES, default=0)

要在 Factory Boy 中为选择生成一个随机值，我会使用 factory.fuzzy.FuzzyChoice，但这只会选择 2 个项目的迭代。它不能采用所选迭代器的第一项。例如：

工厂

class IceCreamProductFactory(factory.django.DjangoModelFactory):
    class Meta:
        model = IceCreamProduct

    type = factory.fuzzy.FuzzyChoice(IceCreamProduct.PRODUCT_TYPES)

错误

TypeError: int() argument must be a string, a bytes-like object or a number, not 'tuple'

获取元组的第一项是不可能的。例如：

工厂

class IceCreamProductFactory(factory.django.DjangoModelFactory):
    class Meta:
        model = IceCreamProduct

    type = factory.fuzzy.FuzzyChoice(IceCreamProduct.PRODUCT_TYPES)[0]

错误

TypeError: 'FuzzyChoice' object does not support indexing

可以使用默认的 Python 随机迭代器，但这会在声明时生成一个值，因此每个工厂对象都将具有相同的随机值。例如：

工厂

class IceCreamProductFactory(factory.django.DjangoModelFactory):
    class Meta:
        model = IceCreamProduct

    type = random.choice(IceCreamProduct.PRODUCT_TYPES)][0]

如何在 Factory Boy 中解决这个问题？我需要创建自定义 FuzzyAttribute 吗？（如果是，请举个例子）

Answer 1

您不需要 FuzzyAttribute。

您可以通过执行以下操作来限制可能的值并仅将每种产品类型的 int 值提供给 FuzzyChoice：

PRODUCT_IDS = [x[0] for x in IceCreamProduct.PRODUCT_TYPES]
class IceCreamProductFactory(factory.django.DjangoModelFactory):
    class Meta:
        model = IceCreamProduct

    type = factory.fuzzy.FuzzyChoice(PRODUCT_IDS)

它应该完成工作。

请注意模糊模块最近已被弃用，请参阅（https://factoryboy.readthedocs.org/en/latest/fuzzy.html），您可能想改用 LazyFunction。

Answer 2

以下是我如何按照 lothiraldan 的建议使用 factory.LazyFunction 做到这一点：

import random

...


def get_license_type():
    "Return a random license type from available choices."
    lt_choices = [x[0] for x in choices.LICENSE_TYPE_CHOICES]
    return random.choice(lt_choices)


def get_line_type():
    "Return a random line type from available choices."
    lt_choices = [x[0] for x in choices.LINE_TYPE_CHOICES]
    return random.choice(lt_choices)


class ProductFactory(ModelFactory):
    name = factory.Faker('name')
    description = factory.Faker('text')
    license_type = factory.LazyFunction(get_license_type)
    line_type = factory.LazyFunction(get_line_type)

    class Meta:
        model = 'products.ProductBaseV2'

Answer 3

因为我必须对很多模型执行此操作，所以我提出了 erichonkanen 解决方案的更抽象版本。我定义了一个助手 class，我把它放在项目的顶级测试目录中，并将其导入到包含工厂的模块中：

test/helpers.py

import factory
import random


class ModelFieldLazyChoice(factory.LazyFunction):
    def __init__(self, model_class, field, *args, **kwargs):
        choices = [choice[0] for choice in model_class._meta.get_field(field).choices]
        super(ModelFieldLazyChoice, self).__init__(
            function=lambda: random.choice(choices),
            *args, **kwargs
        )

并在 app/factories.py

from app.models import IceCreamProduct
from test.helpers import ModelFieldLazyChoice

class IceCreamProductFactory(factory.django.DjangoModelFactory):
    class Meta:
        model = IceCreamProduct

    type = ModelFieldLazyChoice(IceCreamProduct, 'type')

Answer 4

你可以这么简单

class IceCreamProductFactory(factory.django.DjangoModelFactory):
    icecream_flavour = factory.Faker(
        'random_element', elements=[x[0] for x in IceCreamProduct.PRODUCT_TYPES]
    )

    class Meta:
        model = IceCreamProduct

PS。不要使用 type 作为属性，it is a bad practice to use a built-in function name as an attribute

Answer 5

如果您做出选择 class-based...

class IceCreamProduct(models.Model):
    class ProductTypes(models.TextChoices):
        soft_ice_crem = (0, 'Soft Ice Cream')
        hard_ice_cream = (1, 'Hard Ice Cream')
        ...

class IceCreamProductFactory(factory.django.DjangoModelFactory):
    class Meta:
        model = IceCreamProduct

    type = factory.fuzzy.FuzzyChoice(IceCreamProduct.ProductTypes)
    ...

Factory Boy 随机选择带有字段选项的字段 "choices"

Factory Boy random choice for a field with field option "choices"

python

django

factory

django-testing

factory-boy