Refs #12990 -- Moved CheckFieldDefaultMixin to the django.db.models.fields.mixins.

5 files changed, 33 insertions, 34 deletions

diff --git a/django/contrib/postgres/fields/array.py b/django/contrib/postgres/fields/array.py
index 1180795e8f..f8ce7911ef 100644
--- a/django/contrib/postgres/fields/array.py
+++ b/django/contrib/postgres/fields/array.py
@@ -5,11 +5,11 @@ from django.contrib.postgres.forms import SimpleArrayField
 from django.contrib.postgres.validators import ArrayMaxLengthValidator
 from django.core import checks, exceptions
 from django.db.models import Field, IntegerField, Transform
+from django.db.models.fields.mixins import CheckFieldDefaultMixin
 from django.db.models.lookups import Exact, In
 from django.utils.translation import gettext_lazy as _
 
 from ..utils import prefix_validation_error
-from .mixins import CheckFieldDefaultMixin
 from .utils import AttributeSetter
 
 __all__ = ['ArrayField']
diff --git a/django/contrib/postgres/fields/hstore.py b/django/contrib/postgres/fields/hstore.py
index 0889f600a5..2ec5766041 100644
--- a/django/contrib/postgres/fields/hstore.py
+++ b/django/contrib/postgres/fields/hstore.py
@@ -4,10 +4,9 @@ from django.contrib.postgres import forms, lookups
 from django.contrib.postgres.fields.array import ArrayField
 from django.core import exceptions
 from django.db.models import Field, TextField, Transform
+from django.db.models.fields.mixins import CheckFieldDefaultMixin
 from django.utils.translation import gettext_lazy as _
 
-from .mixins import CheckFieldDefaultMixin
-
 __all__ = ['HStoreField']
 
 
diff --git a/django/contrib/postgres/fields/jsonb.py b/django/contrib/postgres/fields/jsonb.py
index 30c48a6018..c402dd19d8 100644
--- a/django/contrib/postgres/fields/jsonb.py
+++ b/django/contrib/postgres/fields/jsonb.py
@@ -7,10 +7,9 @@ from django.core import exceptions
 from django.db.models import (
     Field, TextField, Transform, lookups as builtin_lookups,
 )
+from django.db.models.fields.mixins import CheckFieldDefaultMixin
 from django.utils.translation import gettext_lazy as _
 
-from .mixins import CheckFieldDefaultMixin
-
 __all__ = ['JSONField']
 
 
diff --git a/django/contrib/postgres/fields/mixins.py b/django/contrib/postgres/fields/mixins.py
deleted file mode 100644
index 254b80c4a2..0000000000
--- a/django/contrib/postgres/fields/mixins.py
+++ /dev/null
@@ -1,29 +0,0 @@
-from django.core import checks
-
-
-class CheckFieldDefaultMixin:
-    _default_hint = ('<valid default>', '<invalid default>')
-
-    def _check_default(self):
-        if self.has_default() and self.default is not None and not callable(self.default):
-            return [
-                checks.Warning(
-                    "%s default should be a callable instead of an instance so "
-                    "that it's not shared between all field instances." % (
-                        self.__class__.__name__,
-                    ),
-                    hint=(
-                        'Use a callable instead, e.g., use `%s` instead of '
-                        '`%s`.' % self._default_hint
-                    ),
-                    obj=self,
-                    id='postgres.E003',
-                )
-            ]
-        else:
-            return []
-
-    def check(self, **kwargs):
-        errors = super().check(**kwargs)
-        errors.extend(self._check_default())
-        return errors
diff --git a/django/db/models/fields/mixins.py b/django/db/models/fields/mixins.py
index c6dbc4ec5e..3afa8d9304 100644
--- a/django/db/models/fields/mixins.py
+++ b/django/db/models/fields/mixins.py
@@ -1,3 +1,5 @@
+from django.core import checks
+
 NOT_PROVIDED = object()
 
 
@@ -24,3 +26,31 @@ class FieldCacheMixin:
 
     def delete_cached_value(self, instance):
         del instance._state.fields_cache[self.get_cache_name()]
+
+
+class CheckFieldDefaultMixin:
+    _default_hint = ('<valid default>', '<invalid default>')
+
+    def _check_default(self):
+        if self.has_default() and self.default is not None and not callable(self.default):
+            return [
+                checks.Warning(
+                    "%s default should be a callable instead of an instance "
+                    "so that it's not shared between all field instances." % (
+                        self.__class__.__name__,
+                    ),
+                    hint=(
+                        'Use a callable instead, e.g., use `%s` instead of '
+                        '`%s`.' % self._default_hint
+                    ),
+                    obj=self,
+                    id='fields.E010',
+                )
+            ]
+        else:
+            return []
+
+    def check(self, **kwargs):
+        errors = super().check(**kwargs)
+        errors.extend(self._check_default())
+        return errors