Fixed #23861 -- Added an API to deprecate model fields.

Thanks Markus Holterman and Berker Peksag for review.

1 files changed, 83 insertions, 0 deletions

diff --git a/tests/check_framework/test_model_field_deprecation.py b/tests/check_framework/test_model_field_deprecation.py
new file mode 100644
index 0000000000..1bb8344749
--- /dev/null
+++ b/tests/check_framework/test_model_field_deprecation.py
@@ -0,0 +1,83 @@
+from django.db import models
+from django.core import checks
+from django.test import SimpleTestCase
+
+
+class TestDeprecatedField(SimpleTestCase):
+    def test_default_details(self):
+        class MyField(models.Field):
+            system_check_deprecated_details = {}
+
+        class Model(models.Model):
+            name = MyField()
+
+        model = Model()
+        self.assertEqual(model.check(), [
+            checks.Warning(
+                msg='MyField has been deprecated.',
+                hint=None,
+                obj=Model._meta.get_field('name'),
+                id='fields.WXXX',
+            )
+        ])
+
+    def test_user_specified_details(self):
+        class MyField(models.Field):
+            system_check_deprecated_details = {
+                'msg': 'This field is deprecated and will be removed soon.',
+                'hint': 'Use something else.',
+                'id': 'fields.W999',
+            }
+
+        class Model(models.Model):
+            name = MyField()
+
+        model = Model()
+        self.assertEqual(model.check(), [
+            checks.Warning(
+                msg='This field is deprecated and will be removed soon.',
+                hint='Use something else.',
+                obj=Model._meta.get_field('name'),
+                id='fields.W999',
+            )
+        ])
+
+
+class TestRemovedField(SimpleTestCase):
+    def test_default_details(self):
+        class MyField(models.Field):
+            system_check_removed_details = {}
+
+        class Model(models.Model):
+            name = MyField()
+
+        model = Model()
+        self.assertEqual(model.check(), [
+            checks.Error(
+                msg='MyField has been removed except for support in historical migrations.',
+                hint=None,
+                obj=Model._meta.get_field('name'),
+                id='fields.EXXX',
+            )
+        ])
+
+    def test_user_specified_details(self):
+        class MyField(models.Field):
+            system_check_removed_details = {
+                'msg': 'Support for this field is gone.',
+                'hint': 'Use something else.',
+                'id': 'fields.E999',
+            }
+
+        class Model(models.Model):
+            name = MyField()
+
+        model = Model()
+        self.assertEqual(model.check(), [
+            checks.Error(
+                msg='Support for this field is gone.',
+                hint='Use something else.',
+                obj=Model._meta.get_field('name'),
+                id='fields.E999',
+            )
+        ])