fix check constraint parsing, closes #36

Author: kalekseev

.gitignore

@@ -8,7 +8,5 @@ __pycache__
 /build
 /dist
 /.mypy_cache
-
-# Devenv
-.devenv*
-devenv.local.nix
+/.env*
+/pyrightconfig.json

src/extra_checks/checks/model_field_checks.py

@@ -295,12 +295,16 @@ def apply(
                 field_choices.append("")
             in_name = f"{field.name}__in"
             for constraint in model._meta.constraints:
-                if isinstance(constraint, models.CheckConstraint):
-                    conditions = dict(constraint.check.children)  # type: ignore
-                    if in_name in conditions and set(field_choices) == set(
-                        conditions[in_name]
-                    ):
-                        return
+                if isinstance(constraint, models.CheckConstraint) and isinstance(
+                    constraint.check, models.Q
+                ):
+                    for entry in constraint.check.children:
+                        if (
+                            isinstance(entry, tuple)
+                            and entry[0] == in_name
+                            and set(field_choices) == set(entry[1])
+                        ):
+                            return
             check = f'models.Q({in_name}=[{", ".join([self._repr_choice(c) for c in field_choices])}])'
             yield self.message(
                 "Field with choices must have companion CheckConstraint to enforce choices on database level.",

tests/example/models.py

@@ -174,6 +174,7 @@ class ChoicesConstraint(models.Model):
     integer_blank_invalid = models.IntegerField(
         choices=[(1, "One"), (2, "Two")], blank=True, null=True
     )
+    url = models.URLField(blank=True, null=True)
 
     class Meta:
         constraints = [
@@ -199,6 +200,19 @@ class Meta:
                 name="integer_blank_invalid",
                 check=models.Q(integer_blank_invalid__in=(1, 2, "")),
             ),
+            models.CheckConstraint(
+                name="unrelated_constraint",
+                check=(
+                    models.Q(url=None)
+                    | (
+                        (
+                            models.Q(url__startswith="http://")
+                            | models.Q(url__startswith="https://")
+                        )
+                        & models.Q(url__length__lte=2000)
+                    )
+                ),
+            ),
         ]