CODEWITHSUNDEEP
pythondjango
James Lin
James Lin

Reputation: 26538

Django self.assertEqual comparing 2 new unsaved objects

Lets say I have a CustomerProfile model

class CustomerProfile(models.Model):
    billing_profile = models.ForeignKey(...)

and when I run the assertEqual on 2 unsaved objects, it raises AssertionError

self.assertEqual(
    CustomerProfile(billing_profile=default_profile), 
    CustomerProfile(billing_profile=default_profile)
)

Gives the following error:

AssertionError: <CustomerProfile: Full Charge None> != <CustomerProfile: Full Charge None>

I don't understand why because the instance id would not have been populated since it's unsaved.

Upvotes: 1

Views: 513

Answers (1)

wim
wim

Reputation: 362836

There is no special support in assertEqual for comparing Django models. Unless the models have been saved (i.e. have a primary key) then they are comparing by identity (CPython: memory location), which will always be different for two separate unsaved model instances, even if every field is the same.

To compare unsaved model instances based on content, you would need to manually check that the data in all the relevant fields are equal. Third-party testfixtures has a helper for this: see django_compare.

Upvotes: 2

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