Django test assert not equal-CodePudding

Trying to test selector layer im my app, but django dont pass simle test. Querysets looks quite similar, maybe i lost something.

test.py

from django.test import TestCase

from books.models import Author, Book
from books.selectors import get_books


class SelectorTest(TestCase):
    def setUp(self):
        self.author = Author.objects.create(
            name='test_author'
        )
        self.book = Book.objects.create(
            name='test_book',
            category='Drama',
            release_date='2001-01-01',
            author=self.author,
            is_read=True
        )

    def test_get_books(self):
         self.assertEqual(get_books(), Book.objects.all())

selectors.py

from django.db.models.query import QuerySet

from books.models import Book


def get_books() -> QuerySet[Book]:
    """
    Return all objects of Book model.
    """
    books = Book.objects.all()

    return books

assertion error

AssertionError: <QuerySet [<Book: test_book>]> != <QuerySet [<Book: test_book>]>

CodePudding user response：

To test that two querysets return the same objects but not necessarily in the same order (assuming both query the same underlying Model, of course):

qs1  = Book.objects.all()
qs2 = get_books()
pk1 = qs1.values_list( 'pk', flat=True)
pk2 = q2s.values_list( 'pk', flat=True)

self.assertEqual ( set(pk1), set(pk2) )

This makes a reasonably useful message when the test fails. You get the pks which are in one and not the other identified, not just a not equal" message.

I think if you use list() instead of set() you get to check that both return the same objects in the same order.

CodePudding user response：

You can use the TransactionTestCase.assertQuerysetEqual assertion from Django's TestCase class. Check the documentation here.

In your case:

    # …

    def test_get_books(self):
         self.assertQuerysetEqual(get_books(), Book.objects.all())