Refs #26678 -- Added tests for add()/remove() by reference with to_field

tests/m2m_and_m2o/models.py

@@ -7,13 +7,14 @@
 
 
 class User(models.Model):
-    username = models.CharField(max_length=20)
+    username = models.CharField(max_length=20, unique=True)
 
 
 class Issue(models.Model):
     num = models.IntegerField()
     cc = models.ManyToManyField(User, blank=True, related_name='test_issue_cc')
     client = models.ForeignKey(User, models.CASCADE, related_name='test_issue_client')
+    users = models.ManyToManyField(User, through='UserIssue')
 
     class Meta:
         ordering = ('num',)
@@ -22,5 +23,10 @@ def __str__(self):
         return str(self.num)
 
 
+class UserIssue(models.Model):
+    user = models.ForeignKey(User, models.CASCADE, to_field='username')
+    issue = models.ForeignKey(Issue, models.CASCADE)
+
+
 class StringReferenceModel(models.Model):
     others = models.ManyToManyField('StringReferenceModel')

tests/m2m_and_m2o/tests.py

@@ -27,7 +27,7 @@ def test_m2m_and_m2o(self):
         i3 = Issue(num=3)
         i3.client = g
         i3.save()
-        i3.cc.add(r)
+        i3.cc.add(r.pk)
 
         self.assertQuerysetEqual(
             Issue.objects.filter(client=r.id), [
@@ -80,6 +80,46 @@ def test_m2m_and_m2o(self):
             lambda i: i.num
         )
 
+    def test_m2m_add_and_remove_with_through_model(self):
+        r = User.objects.create(username='russell')
+        t = User.objects.create(username='tobias')
+
+        i = Issue(num=1)
+        i.client = r
+        i.save()
+
+        i.users.add(r)
+        i.users.add(t.username)
+
+        self.assertQuerysetEqual(
+            User.objects.filter(issue=i.id).order_by('id'),
+            [r.pk, t.pk],
+            lambda u: u.pk,
+        )
+
+        i.users.remove(r.username)
+        i.users.remove(t)
+
+        self.assertQuerysetEqual(
+            User.objects.filter(issue=i.id).order_by('id'),
+            [],
+        )
+
+        i.users.add(r, t.username)
+
+        self.assertQuerysetEqual(
+            User.objects.filter(issue=i.id).order_by('id'),
+            [r.pk, t.pk],
+            lambda t: t.pk,
+        )
+
+        i.users.remove(t.username, r)
+
+        self.assertQuerysetEqual(
+            User.objects.filter(issue=i.id).order_by('id'),
+            [],
+        )
+
 
 class RelatedObjectUnicodeTests(TestCase):
     def test_m2m_with_unicode_reference(self):