Merge pull request #2346 from Markush2010/ticket21905

Fixed #21905 -- Add info message if DateField or TimeField use a fixed value

django/db/models/fields/__init__.py

@@ -1079,6 +1079,7 @@ class DateTimeCheckMixin(object):
     def check(self, **kwargs):
         errors = super(DateTimeCheckMixin, self).check(**kwargs)
         errors.extend(self._check_mutually_exclusive_options())
+        errors.extend(self._check_fix_default_value())
         return errors
 
     def _check_mutually_exclusive_options(self):
@@ -1103,6 +1104,9 @@ class DateTimeCheckMixin(object):
         else:
             return []
 
+    def _check_fix_default_value(self):
+        return []
+
 
 class DateField(DateTimeCheckMixin, Field):
     empty_strings_allowed = False
@@ -1122,6 +1126,49 @@ class DateField(DateTimeCheckMixin, Field):
             kwargs['blank'] = True
         super(DateField, self).__init__(verbose_name, name, **kwargs)
 
+    def _check_fix_default_value(self):
+        """
+        Adds a warning to the checks framework stating, that using an actual
+        date or datetime value is probably wrong; it's only being evaluated on
+        server start-up.
+
+        For details see ticket #21905
+        """
+        if not self.has_default():
+            return []
+
+        now = timezone.now()
+        if not timezone.is_naive(now):
+            now = timezone.make_naive(now, timezone.utc)
+        value = self.default
+        if isinstance(value, datetime.datetime):
+            if not timezone.is_naive(value):
+                value = timezone.make_naive(value, timezone.utc)
+            value = value.date()
+        elif isinstance(value, datetime.date):
+            # Nothing to do, as dates don't have tz information
+            pass
+        else:
+            # No explicit date / datetime value -- no checks necessary
+            return []
+        offset = datetime.timedelta(days=1)
+        lower = (now - offset).date()
+        upper = (now + offset).date()
+        if lower <= value <= upper:
+            return [
+                checks.Warning(
+                    'Fixed default value provided.',
+                    hint='It seems you set a fixed date / time / datetime '
+                         'value as default for this field. This may not be '
+                         'what you want. If you want to have the current date '
+                         'as default, use `django.utils.timezone.now`',
+                    obj=self,
+                    id='fields.W161',
+                )
+            ]
+
+        return []
+
     def deconstruct(self):
         name, path, args, kwargs = super(DateField, self).deconstruct()
         if self.auto_now:
@@ -1226,6 +1273,52 @@ class DateTimeField(DateField):
 
     # __init__ is inherited from DateField
 
+    def _check_fix_default_value(self):
+        """
+        Adds a warning to the checks framework stating, that using an actual
+        date or datetime value is probably wrong; it's only being evaluated on
+        server start-up.
+
+        For details see ticket #21905
+        """
+        if not self.has_default():
+            return []
+
+        now = timezone.now()
+        if not timezone.is_naive(now):
+            now = timezone.make_naive(now, timezone.utc)
+        value = self.default
+        if isinstance(value, datetime.datetime):
+            second_offset = datetime.timedelta(seconds=10)
+            lower = now - second_offset
+            upper = now + second_offset
+            if timezone.is_aware(value):
+                value = timezone.make_naive(value, timezone.utc)
+        elif isinstance(value, datetime.date):
+            second_offset = datetime.timedelta(seconds=10)
+            lower = now - second_offset
+            lower = datetime.datetime(lower.year, lower.month, lower.day)
+            upper = now + second_offset
+            upper = datetime.datetime(upper.year, upper.month, upper.day)
+            value = datetime.datetime(value.year, value.month, value.day)
+        else:
+            # No explicit date / datetime value -- no checks necessary
+            return []
+        if lower <= value <= upper:
+            return [
+                checks.Warning(
+                    'Fixed default value provided.',
+                    hint='It seems you set a fixed date / time / datetime '
+                         'value as default for this field. This may not be '
+                         'what you want. If you want to have the current date '
+                         'as default, use `django.utils.timezone.now`',
+                    obj=self,
+                    id='fields.W161',
+                )
+            ]
+
+        return []
+
     def get_internal_type(self):
         return "DateTimeField"
 
@@ -1935,6 +2028,52 @@ class TimeField(DateTimeCheckMixin, Field):
             kwargs['blank'] = True
         super(TimeField, self).__init__(verbose_name, name, **kwargs)
 
+    def _check_fix_default_value(self):
+        """
+        Adds a warning to the checks framework stating, that using an actual
+        time or datetime value is probably wrong; it's only being evaluated on
+        server start-up.
+
+        For details see ticket #21905
+        """
+        if not self.has_default():
+            return []
+
+        now = timezone.now()
+        if not timezone.is_naive(now):
+            now = timezone.make_naive(now, timezone.utc)
+        value = self.default
+        if isinstance(value, datetime.datetime):
+            second_offset = datetime.timedelta(seconds=10)
+            lower = now - second_offset
+            upper = now + second_offset
+            if timezone.is_aware(value):
+                value = timezone.make_naive(value, timezone.utc)
+        elif isinstance(value, datetime.time):
+            second_offset = datetime.timedelta(seconds=10)
+            lower = now - second_offset
+            upper = now + second_offset
+            value = datetime.datetime.combine(now.date(), value)
+            if timezone.is_aware(value):
+                value = timezone.make_naive(value, timezone.utc).time()
+        else:
+            # No explicit time / datetime value -- no checks necessary
+            return []
+        if lower <= value <= upper:
+            return [
+                checks.Warning(
+                    'Fixed default value provided.',
+                    hint='It seems you set a fixed date / time / datetime '
+                         'value as default for this field. This may not be '
+                         'what you want. If you want to have the current date '
+                         'as default, use `django.utils.timezone.now`',
+                    obj=self,
+                    id='fields.W161',
+                )
+            ]
+
+        return []
+
     def deconstruct(self):
         name, path, args, kwargs = super(TimeField, self).deconstruct()
         if self.auto_now is not False:

docs/ref/checks.txt

@@ -68,6 +68,8 @@ Fields
 * **fields.E140**: FilePathFields must have either ``allow_files`` or ``allow_folders`` set to True.
 * **fields.E150**: GenericIPAddressFields cannot accept blank values if null values are not allowed, as blank values are stored as nulls.
 * **fields.E160**: The options ``auto_now``, ``auto_now_add``, and ``default`` are mutually exclusive. Only one of these options may be present.
+* **fields.W161**: Fixed default value provided.
+
 
 File Fields
 ~~~~~~~~~~~

tests/invalid_models_tests/test_ordinary_fields.py

@@ -1,11 +1,12 @@
 # -*- encoding: utf-8 -*-
 from __future__ import unicode_literals
 
-from datetime import datetime
 import unittest
 
-from django.core.checks import Error
+from django.core.checks import Error, Warning as DjangoWarning
 from django.db import connection, models
+from django.test.utils import override_settings
+from django.utils.timezone import make_aware, now
 
 from .base import IsolatedModelsTestCase
 
@@ -198,6 +199,116 @@ class CharFieldTests(IsolatedModelsTestCase):
         self.assertEqual(errors, expected)
 
 
+class DateFieldTests(IsolatedModelsTestCase):
+
+    def test_auto_now_and_auto_now_add_raise_error(self):
+        class Model(models.Model):
+            field0 = models.DateTimeField(auto_now=True, auto_now_add=True, default=now)
+            field1 = models.DateTimeField(auto_now=True, auto_now_add=False, default=now)
+            field2 = models.DateTimeField(auto_now=False, auto_now_add=True, default=now)
+            field3 = models.DateTimeField(auto_now=True, auto_now_add=True, default=None)
+            
+        expected = []
+        checks = []
+        for i in range(4):
+            field = Model._meta.get_field('field%d' % i)
+            expected.append(Error(
+                "The options auto_now, auto_now_add, and default "
+                "are mutually exclusive. Only one of these options "
+                "may be present.",
+                hint=None,
+                obj=field,
+                id='fields.E160',
+            ))
+            checks.extend(field.check())
+            self.assertEqual(checks, expected)
+
+    def test_fix_default_value(self):
+        class Model(models.Model):
+            field_dt = models.DateField(default=now())
+            field_d = models.DateField(default=now().date())
+            field_now = models.DateField(default=now)
+
+        field_dt = Model._meta.get_field('field_dt')
+        field_d = Model._meta.get_field('field_d')
+        field_now = Model._meta.get_field('field_now')
+        errors = field_dt.check()
+        errors.extend(field_d.check())
+        errors.extend(field_now.check())  # doesn't raise a warning
+        expected = [
+            DjangoWarning(
+                'Fixed default value provided.',
+                hint='It seems you set a fixed date / time / datetime '
+                     'value as default for this field. This may not be '
+                     'what you want. If you want to have the current date '
+                     'as default, use `django.utils.timezone.now`',
+                obj=field_dt,
+                id='fields.W161',
+            ),
+            DjangoWarning(
+                'Fixed default value provided.',
+                hint='It seems you set a fixed date / time / datetime '
+                     'value as default for this field. This may not be '
+                     'what you want. If you want to have the current date '
+                     'as default, use `django.utils.timezone.now`',
+                obj=field_d,
+                id='fields.W161',
+            )
+        ]
+        maxDiff = self.maxDiff
+        self.maxDiff = None
+        self.assertEqual(errors, expected)
+        self.maxDiff = maxDiff
+
+    @override_settings(USE_TZ=True)
+    def test_fix_default_value_tz(self):
+        self.test_fix_default_value()
+
+
+class DateTimeFieldTests(IsolatedModelsTestCase):
+
+    def test_fix_default_value(self):
+        class Model(models.Model):
+            field_dt = models.DateTimeField(default=now())
+            field_d = models.DateTimeField(default=now().date())
+            field_now = models.DateTimeField(default=now)
+
+        field_dt = Model._meta.get_field('field_dt')
+        field_d = Model._meta.get_field('field_d')
+        field_now = Model._meta.get_field('field_now')
+        errors = field_dt.check()
+        errors.extend(field_d.check())
+        errors.extend(field_now.check())  # doesn't raise a warning
+        expected = [
+            DjangoWarning(
+                'Fixed default value provided.',
+                hint='It seems you set a fixed date / time / datetime '
+                     'value as default for this field. This may not be '
+                     'what you want. If you want to have the current date '
+                     'as default, use `django.utils.timezone.now`',
+                obj=field_dt,
+                id='fields.W161',
+            ),
+            DjangoWarning(
+                'Fixed default value provided.',
+                hint='It seems you set a fixed date / time / datetime '
+                     'value as default for this field. This may not be '
+                     'what you want. If you want to have the current date '
+                     'as default, use `django.utils.timezone.now`',
+                obj=field_d,
+                id='fields.W161',
+            )
+        ]
+        maxDiff = self.maxDiff
+        self.maxDiff = None
+        self.assertEqual(errors, expected)
+        self.maxDiff = maxDiff
+
+    @override_settings(USE_TZ=True)
+    def test_fix_default_value_tz(self):
+        self.test_fix_default_value()
+
+
 class DecimalFieldTests(IsolatedModelsTestCase):
 
     def test_required_attributes(self):
@@ -402,28 +513,45 @@ class ImageFieldTests(IsolatedModelsTestCase):
         self.assertEqual(errors, expected)
 
 
-class DateFieldTests(IsolatedModelsTestCase):
+class TimeFieldTests(IsolatedModelsTestCase):
 
-    def test_auto_now_and_auto_now_add_raise_error(self):
-            dn = datetime.now
-            mutually_exclusive_combinations = (
-                (True, True, dn),
-                (True, False, dn),
-                (False, True, dn),
-                (True, True, None)
+    def test_fix_default_value(self):
+        class Model(models.Model):
+            field_dt = models.TimeField(default=now())
+            field_t = models.TimeField(default=now().time())
+            field_now = models.DateField(default=now)
+
+        field_dt = Model._meta.get_field('field_dt')
+        field_t = Model._meta.get_field('field_t')
+        field_now = Model._meta.get_field('field_now')
+        errors = field_dt.check()
+        errors.extend(field_t.check())
+        errors.extend(field_now.check())  # doesn't raise a warning
+        expected = [
+            DjangoWarning(
+                'Fixed default value provided.',
+                hint='It seems you set a fixed date / time / datetime '
+                     'value as default for this field. This may not be '
+                     'what you want. If you want to have the current date '
+                     'as default, use `django.utils.timezone.now`',
+                obj=field_dt,
+                id='fields.W161',
+            ),
+            DjangoWarning(
+                'Fixed default value provided.',
+                hint='It seems you set a fixed date / time / datetime '
+                     'value as default for this field. This may not be '
+                     'what you want. If you want to have the current date '
+                     'as default, use `django.utils.timezone.now`',
+                obj=field_t,
+                id='fields.W161',
             )
+        ]
+        maxDiff = self.maxDiff
+        self.maxDiff = None
+        self.assertEqual(errors, expected)
+        self.maxDiff = maxDiff
 
-            for auto_now, auto_now_add, default in mutually_exclusive_combinations:
-                field = models.DateTimeField(name="field", auto_now=auto_now,
-                                             auto_now_add=auto_now_add,
-                                             default=default)
-                expected = [Error(
-                    "The options auto_now, auto_now_add, and default "
-                    "are mutually exclusive. Only one of these options "
-                    "may be present.",
-                    hint=None,
-                    obj=field,
-                    id='fields.E160',
-                )]
-                checks = field.check()
-                self.assertEqual(checks, expected)
+    @override_settings(USE_TZ=True)
+    def test_fix_default_value_tz(self):
+        self.test_fix_default_value()