Edited model and field checks for grammar and consistency.

django/core/checks/model_checks.py

@@ -36,14 +36,14 @@ def check_model_signals(app_configs=None, **kwargs):
                         description = "An instance of the `%s` class" % receiver.__class__.__name__
                     errors.append(
                         Error(
-                            "%s was connected to the `%s` signal "
+                            "%s was connected to the '%s' signal "
                             "with a lazy reference to the '%s' sender, "
                             "which has not been installed." % (
                                 description, name, '.'.join(reference)
                             ),
                             obj=receiver.__module__,
                             hint=None,
-                            id='E014'
+                            id='signals.E001'
                         )
                     )
     return errors

django/db/models/fields/__init__.py

@@ -197,10 +197,10 @@ class Field(RegisterLookupMixin):
         if self.name.endswith('_'):
             return [
                 checks.Error(
-                    'Field names must not end with underscores.',
+                    'Field names must not end with an underscore.',
                     hint=None,
                     obj=self,
-                    id='E001',
+                    id='fields.E001',
                 )
             ]
         elif '__' in self.name:
@@ -209,16 +209,16 @@ class Field(RegisterLookupMixin):
                     'Field names must not contain "__".',
                     hint=None,
                     obj=self,
-                    id='E052',
+                    id='fields.E002',
                 )
             ]
         elif self.name == 'pk':
             return [
                 checks.Error(
-                    'Cannot use "pk" as a field name since it is a reserved name.',
+                    "'pk' is a reserved word that cannot be used as a field name.",
                     hint=None,
                     obj=self,
-                    id='E051',
+                    id='fields.E003',
                 )
             ]
         else:
@@ -230,10 +230,10 @@ class Field(RegisterLookupMixin):
                     not is_iterable(self.choices)):
                 return [
                     checks.Error(
-                        '"choices" must be an iterable (e.g., a list or tuple).',
+                        "'choices' must be an iterable (e.g., a list or tuple).",
                         hint=None,
                         obj=self,
-                        id='E033',
+                        id='fields.E004',
                     )
                 ]
             elif any(isinstance(choice, six.string_types) or
@@ -241,13 +241,11 @@ class Field(RegisterLookupMixin):
                      for choice in self.choices):
                 return [
                     checks.Error(
-                        ('All "choices" elements must be a tuple of two '
-                         'elements (the first one is the actual value '
-                         'to be stored and the second element is '
-                         'the human-readable name).'),
+                        ("'choices' must be an iterable containing "
+                         "(actual value, human readable name) tuples."),
                         hint=None,
                         obj=self,
-                        id='E034',
+                        id='fields.E005',
                     )
                 ]
             else:
@@ -259,10 +257,10 @@ class Field(RegisterLookupMixin):
         if self.db_index not in (None, True, False):
             return [
                 checks.Error(
-                    '"db_index" must be either None, True or False.',
+                    "'db_index' must be None, True or False.",
                     hint=None,
                     obj=self,
-                    id='E035',
+                    id='fields.E006',
                 )
             ]
         else:
@@ -277,10 +275,10 @@ class Field(RegisterLookupMixin):
             return [
                 checks.Error(
                     'Primary keys must not have null=True.',
-                    hint=('Set null=False on the field or '
+                    hint=('Set null=False on the field, or '
                           'remove primary_key=True argument.'),
                     obj=self,
-                    id='E036',
+                    id='fields.E007',
                 )
             ]
         else:
@@ -864,10 +862,10 @@ class AutoField(Field):
         if not self.primary_key:
             return [
                 checks.Error(
-                    'The field must have primary_key=True, because it is an AutoField.',
+                    'AutoFields must set primary_key=True.',
                     hint=None,
                     obj=self,
-                    id='E048',
+                    id='fields.E100',
                 ),
             ]
         else:
@@ -940,10 +938,10 @@ class BooleanField(Field):
         if getattr(self, 'null', False):
             return [
                 checks.Error(
-                    'BooleanFields do not acceps null values.',
+                    'BooleanFields do not accept null values.',
                     hint='Use a NullBooleanField instead.',
                     obj=self,
-                    id='E037',
+                    id='fields.E110',
                 )
             ]
         else:
@@ -1020,19 +1018,19 @@ class CharField(Field):
         except TypeError:
             return [
                 checks.Error(
-                    'The field must have "max_length" attribute.',
+                    "CharFields must define a 'max_length' attribute.",
                     hint=None,
                     obj=self,
-                    id='E038',
+                    id='fields.E120',
                 )
             ]
         except ValueError:
             return [
                 checks.Error(
-                    '"max_length" must be a positive integer.',
+                    "'max_length' must be a positive integer.",
                     hint=None,
                     obj=self,
-                    id='E039',
+                    id='fields.E121',
                 )
             ]
         else:
@@ -1305,24 +1303,16 @@ class DecimalField(Field):
 
     def check(self, **kwargs):
         errors = super(DecimalField, self).check(**kwargs)
-        errors.extend(self._check_decimal_places_and_max_digits(**kwargs))
-        return errors
 
-    def _check_decimal_places_and_max_digits(self, **kwargs):
-        errors = self.__check_decimal_places()
-        errors += self.__check_max_digits()
-        if not errors and int(self.decimal_places) > int(self.max_digits):
-            errors.append(
-                checks.Error(
-                    '"max_digits" must be greater or equal to "decimal_places".',
-                    hint=None,
-                    obj=self,
-                    id='E040',
-                )
-            )
+        digits_errors = self._check_decimal_places()
+        digits_errors.extend(self._check_max_digits())
+        if not digits_errors:
+            errors.extend(self._check_decimal_places_and_max_digits(**kwargs))
+        else:
+            errors.extend(digits_errors)
         return errors
 
-    def __check_decimal_places(self):
+    def _check_decimal_places(self):
         try:
             decimal_places = int(self.decimal_places)
             if decimal_places < 0:
@@ -1330,25 +1320,25 @@ class DecimalField(Field):
         except TypeError:
             return [
                 checks.Error(
-                    'The field requires a "decimal_places" attribute.',
+                    "DecimalFields must define a 'decimal_places' attribute.",
                     hint=None,
                     obj=self,
-                    id='E041',
+                    id='fields.E130',
                 )
             ]
         except ValueError:
             return [
                 checks.Error(
-                    '"decimal_places" attribute must be a non-negative integer.',
+                    "'decimal_places' must be a non-negative integer.",
                     hint=None,
                     obj=self,
-                    id='E042',
+                    id='fields.E131',
                 )
             ]
         else:
             return []
 
-    def __check_max_digits(self):
+    def _check_max_digits(self):
         try:
             max_digits = int(self.max_digits)
             if max_digits <= 0:
@@ -1356,24 +1346,36 @@ class DecimalField(Field):
         except TypeError:
             return [
                 checks.Error(
-                    'The field requires a "max_digits" attribute.',
+                    "DecimalFields must define a 'max_digits' attribute.",
                     hint=None,
                     obj=self,
-                    id='E043',
+                    id='fields.E132',
                 )
             ]
         except ValueError:
             return [
                 checks.Error(
-                    '"max_digits" attribute must be a positive integer.',
+                    "'max_digits' must be a positive integer.",
                     hint=None,
                     obj=self,
-                    id='E044',
+                    id='fields.E133',
                 )
             ]
         else:
             return []
 
+    def _check_decimal_places_and_max_digits(self, **kwargs):
+        if int(self.decimal_places) > int(self.max_digits):
+            return [
+                checks.Error(
+                    "'max_digits' must be greater or equal to 'decimal_places'.",
+                    hint=None,
+                    obj=self,
+                    id='fields.E134',
+                )
+            ]
+        return []
+
     def deconstruct(self):
         name, path, args, kwargs = super(DecimalField, self).deconstruct()
         if self.max_digits:
@@ -1481,10 +1483,10 @@ class FilePathField(Field):
         if not self.allow_files and not self.allow_folders:
             return [
                 checks.Error(
-                    'The field must have either "allow_files" or "allow_folders" set to True.',
+                    "FilePathFields must have either 'allow_files' or 'allow_folders' set to True.",
                     hint=None,
                     obj=self,
-                    id='E045',
+                    id='fields.E140',
                 )
             ]
         return []
@@ -1659,11 +1661,11 @@ class GenericIPAddressField(Field):
         if not getattr(self, 'null', False) and getattr(self, 'blank', False):
             return [
                 checks.Error(
-                    ('The field cannot accept blank values if null values '
-                     'are not allowed, as blank values are stored as null.'),
+                    ('GenericIPAddressFields cannot have blank=True if null=False, '
+                     'as blank values are stored as nulls.'),
                     hint=None,
                     obj=self,
-                    id='E046',
+                    id='fields.E150',
                 )
             ]
         return []

django/db/models/fields/files.py

@@ -246,10 +246,10 @@ class FileField(Field):
         if self._unique_set_explicitly:
             return [
                 checks.Error(
-                    '"unique" is not a valid argument for %s.' % self.__class__.__name__,
+                    "'unique' is not a valid argument for a %s." % self.__class__.__name__,
                     hint=None,
                     obj=self,
-                    id='E049',
+                    id='fields.E200',
                 )
             ]
         else:
@@ -259,10 +259,10 @@ class FileField(Field):
         if self._primary_key_set_explicitly:
             return [
                 checks.Error(
-                    '"primary_key" is not a valid argument for %s.' % self.__class__.__name__,
+                    "'primary_key' is not a valid argument for a %s." % self.__class__.__name__,
                     hint=None,
                     obj=self,
-                    id='E050',
+                    id='fields.E201',
                 )
             ]
         else:
@@ -392,11 +392,11 @@ class ImageField(FileField):
         except ImproperlyConfigured:
             return [
                 checks.Error(
-                    'To use ImageFields, Pillow must be installed.',
+                    'Cannot use ImageField because Pillow is not installed.',
                     hint=('Get Pillow at https://pypi.python.org/pypi/Pillow '
                           'or run command "pip install pillow".'),
                     obj=self,
-                    id='E032',
+                    id='fields.E210',
                 )
             ]
         else:

django/db/models/fields/related.py

@@ -108,13 +108,11 @@ class RelatedField(Field):
         if rel_is_missing and (rel_is_string or not self.rel.to._meta.swapped):
             return [
                 checks.Error(
-                    ('The field has a relation with model %s, which '
-                     'has either not been installed or is abstract.') % model_name,
-                    hint=('Ensure that you did not misspell the model name and '
-                          'the model is not abstract. Does your INSTALLED_APPS '
-                          'setting contain the app where %s is defined?') % model_name,
+                    ("Field defines a relation with model '%s', which "
+                     "is either not installed, or is abstract.") % model_name,
+                    hint=None,
                     obj=self,
-                    id='E030',
+                    id='fields.E300',
                 )
             ]
         return []
@@ -129,11 +127,11 @@ class RelatedField(Field):
             )
             return [
                 checks.Error(
-                    ('The field defines a relation with the model %s, '
-                     'which has been swapped out.') % model,
-                    hint='Update the relation to point at settings.%s' % self.rel.to._meta.swappable,
+                    ("Field defines a relation with the model '%s', "
+                     "which has been swapped out.") % model,
+                    hint="Update the relation to point at 'settings.%s'." % self.rel.to._meta.swappable,
                     obj=self,
-                    id='E029',
+                    id='fields.E301',
                 )
             ]
         return []
@@ -190,22 +188,22 @@ class RelatedField(Field):
             if clash_field.name == rel_name:
                 errors.append(
                     checks.Error(
-                        'Accessor for field %s clashes with field %s.' % (field_name, clash_name),
-                        hint=('Rename field %s or add/change a related_name '
-                              'argument to the definition for field %s.') % (clash_name, field_name),
+                        "Reverse accessor for '%s' clashes with field name '%s'." % (field_name, clash_name),
+                        hint=("Rename field '%s', or add/change a related_name "
+                              "argument to the definition for field '%s'.") % (clash_name, field_name),
                         obj=self,
-                        id='E014',
+                        id='fields.E302',
                     )
                 )
 
             if clash_field.name == rel_query_name:
                 errors.append(
                     checks.Error(
-                        'Reverse query name for field %s clashes with field %s.' % (field_name, clash_name),
-                        hint=('Rename field %s or add/change a related_name '
-                              'argument to the definition for field %s.') % (clash_name, field_name),
+                        "Reverse query name for '%s' clashes with field name '%s'." % (field_name, clash_name),
+                        hint=("Rename field '%s', or add/change a related_name "
+                              "argument to the definition for field '%s'.") % (clash_name, field_name),
                         obj=self,
-                        id='E015',
+                        id='fields.E303',
                     )
                 )
 
@@ -223,22 +221,22 @@ class RelatedField(Field):
             if clash_field.get_accessor_name() == rel_name:
                 errors.append(
                     checks.Error(
-                        'Clash between accessors for %s and %s.' % (field_name, clash_name),
-                        hint=('Add or change a related_name argument '
-                              'to the definition for %s or %s.') % (field_name, clash_name),
+                        "Reverse accessor for '%s' clashes with reverse accessor for '%s'." % (field_name, clash_name),
+                        hint=("Add or change a related_name argument "
+                              "to the definition for '%s' or '%s'.") % (field_name, clash_name),
                         obj=self,
-                        id='E016',
+                        id='fields.E304',
                     )
                 )
 
             if clash_field.get_accessor_name() == rel_query_name:
                 errors.append(
                     checks.Error(
-                        'Clash between reverse query names for %s and %s.' % (field_name, clash_name),
-                        hint=('Add or change a related_name argument '
-                              'to the definition for %s or %s.') % (field_name, clash_name),
+                        "Reverse query name for '%s' clashes with reverse query name for '%s'." % (field_name, clash_name),
+                        hint=("Add or change a related_name argument "
+                              "to the definition for '%s' or '%s'.") % (field_name, clash_name),
                         obj=self,
-                        id='E017',
+                        id='fields.E305',
                     )
                 )
 
@@ -1317,17 +1315,15 @@ class ForeignObject(RelatedField):
         has_unique_field = any(rel_field.unique
             for rel_field in self.foreign_related_fields)
         if not has_unique_field and len(self.foreign_related_fields) > 1:
-            field_combination = ','.join(rel_field.name
+            field_combination = ', '.join("'%s'" % rel_field.name
                 for rel_field in self.foreign_related_fields)
             model_name = self.rel.to.__name__
             return [
                 checks.Error(
-                    ('No unique=True constraint '
-                     'on field combination "%s" under model %s.') % (field_combination, model_name),
-                    hint=('Set unique=True argument on any of the fields '
-                          '"%s" under model %s.') % (field_combination, model_name),
+                    "None of the fields %s on model '%s' have a unique=True constraint." % (field_combination, model_name),
+                    hint=None,
                     obj=self,
-                    id='E018',
+                    id='fields.E310',
                 )
             ]
         elif not has_unique_field:
@@ -1335,11 +1331,11 @@ class ForeignObject(RelatedField):
             model_name = self.rel.to.__name__
             return [
                 checks.Error(
-                    ('%s.%s must have unique=True '
-                     'because it is referenced by a foreign key.') % (model_name, field_name),
+                    ("'%s.%s' must set unique=True "
+                     "because it is referenced by a foreign key.") % (model_name, field_name),
                     hint=None,
                     obj=self,
-                    id='E019',
+                    id='fields.E311',
                 )
             ]
         else:
@@ -1605,19 +1601,19 @@ class ForeignKey(ForeignObject):
         if on_delete == SET_NULL and not self.null:
             return [
                 checks.Error(
-                    'The field specifies on_delete=SET_NULL, but cannot be null.',
-                    hint='Set null=True argument on the field.',
+                    'Field specifies on_delete=SET_NULL, but cannot be null.',
+                    hint='Set null=True argument on the field, or change the on_delete rule.',
                     obj=self,
-                    id='E020',
+                    id='fields.E320',
                 )
             ]
         elif on_delete == SET_DEFAULT and not self.has_default():
             return [
                 checks.Error(
-                    'The field specifies on_delete=SET_DEFAULT, but has no default value.',
-                    hint=None,
+                    'Field specifies on_delete=SET_DEFAULT, but has no default value.',
+                    hint='Set a default value, or change the on_delete rule.',
                     obj=self,
-                    id='E021',
+                    id='fields.E321',
                 )
             ]
         else:
@@ -1864,10 +1860,10 @@ class ManyToManyField(RelatedField):
         if self.unique:
             return [
                 checks.Error(
-                    'ManyToManyFields must not be unique.',
+                    'ManyToManyFields cannot be unique.',
                     hint=None,
                     obj=self,
-                    id='E022',
+                    id='fields.E330',
                 )
             ]
         return []
@@ -1879,13 +1875,11 @@ class ManyToManyField(RelatedField):
             # The relationship model is not installed.
             errors.append(
                 checks.Error(
-                    ('The field specifies a many-to-many relation through model '
-                     '%s, which has not been installed.') % self.rel.through,
-                    hint=('Ensure that you did not misspell the model name and '
-                          'the model is not abstract. Does your INSTALLED_APPS '
-                          'setting contain the app where %s is defined?') % self.rel.through,
+                    ("Field specifies a many-to-many relation through model "
+                     "'%s', which has not been installed.") % self.rel.through,
+                    hint=None,
                     obj=self,
-                    id='E023',
+                    id='fields.E331',
                 )
             )
 
@@ -1914,7 +1908,7 @@ class ManyToManyField(RelatedField):
                         'Many-to-many fields with intermediate tables must not be symmetrical.',
                         hint=None,
                         obj=self,
-                        id='E024',
+                        id='fields.E332',
                     )
                 )
 
@@ -1926,12 +1920,12 @@ class ManyToManyField(RelatedField):
                 if seen_self > 2:
                     errors.append(
                         checks.Error(
-                            ('The model is used as an intermediary model by '
-                             '%s, but it has more than two foreign keys '
-                             'to %s, which is ambiguous and is not permitted.') % (self, from_model_name),
+                            ("The model is used as an intermediate model by "
+                             "'%s', but it has more than two foreign keys "
+                             "to '%s', which is ambiguous.") % (self, from_model_name),
                             hint=None,
                             obj=self.rel.through,
-                            id='E025',
+                            id='fields.E333',
                         )
                     )
 
@@ -1945,41 +1939,41 @@ class ManyToManyField(RelatedField):
                 if seen_from > 1:
                     errors.append(
                         checks.Error(
-                            ('The model is used as an intermediary model by '
-                             '%s, but it has more than one foreign key '
-                             'to %s, which is ambiguous and is not permitted.') % (self, from_model_name),
+                            ("The model is used as an intermediate model by "
+                             "'%s', but it has more than one foreign key "
+                             "from '%s', which is ambiguous.") % (self, from_model_name),
                             hint=('If you want to create a recursive relationship, '
                                   'use ForeignKey("self", symmetrical=False, '
                                   'through="%s").') % relationship_model_name,
                             obj=self,
-                            id='E026',
+                            id='fields.E334',
                         )
                     )
 
                 if seen_to > 1:
                     errors.append(
                         checks.Error(
-                            ('The model is used as an intermediary model by '
-                             '%s, but it has more than one foreign key '
-                             'to %s, which is ambiguous and is not permitted.') % (self, to_model_name),
+                            ("The model is used as an intermediate model by "
+                             "'%s', but it has more than one foreign key "
+                             "to '%s', which is ambiguous.") % (self, to_model_name),
                             hint=('If you want to create a recursive '
                                   'relationship, use ForeignKey("self", '
                                   'symmetrical=False, through="%s").') % relationship_model_name,
                             obj=self,
-                            id='E027',
+                            id='fields.E335',
                         )
                     )
 
                 if seen_from == 0 or seen_to == 0:
                     errors.append(
                         checks.Error(
-                            ('The model is used as an intermediary model by '
-                             '%s, but it misses a foreign key to %s or %s.') % (
+                            ("The model is used as an intermediate model by "
+                             "'%s', but it does not have a foreign key to '%s' or '%s'.") % (
                                 self, from_model_name, to_model_name
                             ),
                             hint=None,
                             obj=self.rel.through,
-                            id='E028',
+                            id='fields.E336',
                         )
                     )
         return errors

tests/contenttypes_tests/tests.py

@@ -233,13 +233,11 @@ class GenericRelationshipTests(IsolatedModelsTestCase):
         errors = Model.rel.field.check()
         expected = [
             checks.Error(
-                ('The field has a relation with model MissingModel, '
-                 'which has either not been installed or is abstract.'),
-                hint=('Ensure that you did not misspell the model name and '
-                      'the model is not abstract. Does your INSTALLED_APPS '
-                      'setting contain the app where MissingModel is defined?'),
+                ("Field defines a relation with model 'MissingModel', "
+                 "which is either not installed, or is abstract."),
+                hint=None,
                 obj=Model.rel.field,
-                id='E030',
+                id='fields.E300',
             )
         ]
         self.assertEqual(errors, expected)
@@ -295,12 +293,12 @@ class GenericRelationshipTests(IsolatedModelsTestCase):
         errors = Model.rel.field.check()
         expected = [
             checks.Error(
-                ('The field defines a relation with the model '
-                 'contenttypes_tests.SwappedModel, '
-                 'which has been swapped out.'),
-                hint='Update the relation to point at settings.TEST_SWAPPED_MODEL',
+                ("Field defines a relation with the model "
+                 "'contenttypes_tests.SwappedModel', "
+                 "which has been swapped out."),
+                hint="Update the relation to point at 'settings.TEST_SWAPPED_MODEL'.",
                 obj=Model.rel.field,
-                id='E029',
+                id='fields.E301',
             )
         ]
         self.assertEqual(errors, expected)
@@ -317,10 +315,10 @@ class GenericRelationshipTests(IsolatedModelsTestCase):
         errors = InvalidBookmark.tags_.field.check()
         expected = [
             checks.Error(
-                'Field names must not end with underscores.',
+                'Field names must not end with an underscore.',
                 hint=None,
                 obj=InvalidBookmark.tags_.field,
-                id='E001',
+                id='fields.E001',
             )
         ]
         self.assertEqual(errors, expected)

tests/invalid_models_tests/test_models.py

@@ -214,16 +214,16 @@ class FieldNamesTests(IsolatedModelsTestCase):
         errors = Model.check()
         expected = [
             Error(
-                'Field names must not end with underscores.',
+                'Field names must not end with an underscore.',
                 hint=None,
                 obj=Model._meta.get_field('field_'),
-                id='E001',
+                id='fields.E001',
             ),
             Error(
-                'Field names must not end with underscores.',
+                'Field names must not end with an underscore.',
                 hint=None,
                 obj=Model._meta.get_field('m2m_'),
-                id='E001',
+                id='fields.E001',
             ),
         ]
         self.assertEqual(errors, expected)
@@ -238,7 +238,7 @@ class FieldNamesTests(IsolatedModelsTestCase):
                 'Field names must not contain "__".',
                 hint=None,
                 obj=Model._meta.get_field('some__field'),
-                id='E052',
+                id='fields.E002',
             )
         ]
         self.assertEqual(errors, expected)
@@ -250,10 +250,10 @@ class FieldNamesTests(IsolatedModelsTestCase):
         errors = Model.check()
         expected = [
             Error(
-                'Cannot use "pk" as a field name since it is a reserved name.',
+                "'pk' is a reserved word that cannot be used as a field name.",
                 hint=None,
                 obj=Model._meta.get_field('pk'),
-                id='E051',
+                id='fields.E003',
             )
         ]
         self.assertEqual(errors, expected)

tests/invalid_models_tests/test_ordinary_fields.py

@@ -35,10 +35,10 @@ class AutoFieldTests(IsolatedModelsTestCase):
         errors = field.check()
         expected = [
             Error(
-                'The field must have primary_key=True, because it is an AutoField.',
+                'AutoFields must set primary_key=True.',
                 hint=None,
                 obj=field,
-                id='E048',
+                id='fields.E100',
             ),
         ]
         self.assertEqual(errors, expected)
@@ -54,10 +54,10 @@ class BooleanFieldTests(IsolatedModelsTestCase):
         errors = field.check()
         expected = [
             Error(
-                'BooleanFields do not acceps null values.',
+                'BooleanFields do not accept null values.',
                 hint='Use a NullBooleanField instead.',
                 obj=field,
-                id='E037',
+                id='fields.E110',
             ),
         ]
         self.assertEqual(errors, expected)
@@ -88,10 +88,10 @@ class CharFieldTests(IsolatedModelsTestCase):
         errors = field.check()
         expected = [
             Error(
-                'The field must have "max_length" attribute.',
+                "CharFields must define a 'max_length' attribute.",
                 hint=None,
                 obj=field,
-                id='E038',
+                id='fields.E120',
             ),
         ]
         self.assertEqual(errors, expected)
@@ -104,10 +104,10 @@ class CharFieldTests(IsolatedModelsTestCase):
         errors = field.check()
         expected = [
             Error(
-                '"max_length" must be a positive integer.',
+                "'max_length' must be a positive integer.",
                 hint=None,
                 obj=field,
-                id='E039',
+                id='fields.E121',
             ),
         ]
         self.assertEqual(errors, expected)
@@ -120,10 +120,10 @@ class CharFieldTests(IsolatedModelsTestCase):
         errors = field.check()
         expected = [
             Error(
-                '"max_length" must be a positive integer.',
+                "'max_length' must be a positive integer.",
                 hint=None,
                 obj=field,
-                id='E039',
+                id='fields.E121',
             ),
         ]
         self.assertEqual(errors, expected)
@@ -136,10 +136,10 @@ class CharFieldTests(IsolatedModelsTestCase):
         errors = field.check()
         expected = [
             Error(
-                '"choices" must be an iterable (e.g., a list or tuple).',
+                "'choices' must be an iterable (e.g., a list or tuple).",
                 hint=None,
                 obj=field,
-                id='E033',
+                id='fields.E004',
             ),
         ]
         self.assertEqual(errors, expected)
@@ -152,12 +152,10 @@ class CharFieldTests(IsolatedModelsTestCase):
         errors = field.check()
         expected = [
             Error(
-                ('All "choices" elements must be a tuple of two elements '
-                 '(the first one is the actual value to be stored '
-                 'and the second element is the human-readable name).'),
+                "'choices' must be an iterable containing (actual value, human readable name) tuples.",
                 hint=None,
                 obj=field,
-                id='E034',
+                id='fields.E005',
             ),
         ]
         self.assertEqual(errors, expected)
@@ -170,10 +168,10 @@ class CharFieldTests(IsolatedModelsTestCase):
         errors = field.check()
         expected = [
             Error(
-                '"db_index" must be either None, True or False.',
+                "'db_index' must be None, True or False.",
                 hint=None,
                 obj=field,
-                id='E035',
+                id='fields.E006',
             ),
         ]
         self.assertEqual(errors, expected)
@@ -210,16 +208,16 @@ class DecimalFieldTests(IsolatedModelsTestCase):
         errors = field.check()
         expected = [
             Error(
-                'The field requires a "decimal_places" attribute.',
+                "DecimalFields must define a 'decimal_places' attribute.",
                 hint=None,
                 obj=field,
-                id='E041',
+                id='fields.E130',
             ),
             Error(
-                'The field requires a "max_digits" attribute.',
+                "DecimalFields must define a 'max_digits' attribute.",
                 hint=None,
                 obj=field,
-                id='E043',
+                id='fields.E132',
             ),
         ]
         self.assertEqual(errors, expected)
@@ -232,16 +230,16 @@ class DecimalFieldTests(IsolatedModelsTestCase):
         errors = field.check()
         expected = [
             Error(
-                '"decimal_places" attribute must be a non-negative integer.',
+                "'decimal_places' must be a non-negative integer.",
                 hint=None,
                 obj=field,
-                id='E042',
+                id='fields.E131',
             ),
             Error(
-                '"max_digits" attribute must be a positive integer.',
+                "'max_digits' must be a positive integer.",
                 hint=None,
                 obj=field,
-                id='E044',
+                id='fields.E133',
             ),
         ]
         self.assertEqual(errors, expected)
@@ -254,16 +252,16 @@ class DecimalFieldTests(IsolatedModelsTestCase):
         errors = field.check()
         expected = [
             Error(
-                '"decimal_places" attribute must be a non-negative integer.',
+                "'decimal_places' must be a non-negative integer.",
                 hint=None,
                 obj=field,
-                id='E042',
+                id='fields.E131',
             ),
             Error(
-                '"max_digits" attribute must be a positive integer.',
+                "'max_digits' must be a positive integer.",
                 hint=None,
                 obj=field,
-                id='E044',
+                id='fields.E133',
             ),
         ]
         self.assertEqual(errors, expected)
@@ -276,10 +274,10 @@ class DecimalFieldTests(IsolatedModelsTestCase):
         errors = field.check()
         expected = [
             Error(
-                '"max_digits" must be greater or equal to "decimal_places".',
+                "'max_digits' must be greater or equal to 'decimal_places'.",
                 hint=None,
                 obj=field,
-                id='E040',
+                id='fields.E134',
             ),
         ]
         self.assertEqual(errors, expected)
@@ -313,10 +311,10 @@ class FileFieldTests(IsolatedModelsTestCase):
         errors = field.check()
         expected = [
             Error(
-                '"unique" is not a valid argument for FileField.',
+                "'unique' is not a valid argument for a FileField.",
                 hint=None,
                 obj=field,
-                id='E049',
+                id='fields.E200',
             )
         ]
         self.assertEqual(errors, expected)
@@ -329,10 +327,10 @@ class FileFieldTests(IsolatedModelsTestCase):
         errors = field.check()
         expected = [
             Error(
-                '"primary_key" is not a valid argument for FileField.',
+                "'primary_key' is not a valid argument for a FileField.",
                 hint=None,
                 obj=field,
-                id='E050',
+                id='fields.E201',
             )
         ]
         self.assertEqual(errors, expected)
@@ -348,10 +346,10 @@ class FilePathFieldTests(IsolatedModelsTestCase):
         errors = field.check()
         expected = [
             Error(
-                'The field must have either "allow_files" or "allow_folders" set to True.',
+                "FilePathFields must have either 'allow_files' or 'allow_folders' set to True.",
                 hint=None,
                 obj=field,
-                id='E045',
+                id='fields.E140',
             ),
         ]
         self.assertEqual(errors, expected)
@@ -367,11 +365,11 @@ class GenericIPAddressFieldTests(IsolatedModelsTestCase):
         errors = field.check()
         expected = [
             Error(
-                ('The field cannot accept blank values if null values '
-                 'are not allowed, as blank values are stored as null.'),
+                ('GenericIPAddressFields cannot have blank=True if null=False, '
+                 'as blank values are stored as nulls.'),
                 hint=None,
                 obj=field,
-                id='E046',
+                id='fields.E150',
             ),
         ]
         self.assertEqual(errors, expected)
@@ -394,11 +392,11 @@ class ImageFieldTests(IsolatedModelsTestCase):
         errors = field.check()
         expected = [] if pillow_installed else [
             Error(
-                'To use ImageFields, Pillow must be installed.',
+                'Cannot use ImageField because Pillow is not installed.',
                 hint=('Get Pillow at https://pypi.python.org/pypi/Pillow '
                       'or run command "pip install pillow".'),
                 obj=field,
-                id='E032',
+                id='fields.E210',
             ),
         ]
         self.assertEqual(errors, expected)

tests/invalid_models_tests/test_relative_fields.py

@@ -34,13 +34,11 @@ class RelativeFieldTests(IsolatedModelsTestCase):
         errors = field.check()
         expected = [
             Error(
-                ('The field has a relation with model Rel1, '
-                 'which has either not been installed or is abstract.'),
-                hint=('Ensure that you did not misspell the model name and '
-                      'the model is not abstract. Does your INSTALLED_APPS '
-                      'setting contain the app where Rel1 is defined?'),
+                ("Field defines a relation with model 'Rel1', "
+                 "which is either not installed, or is abstract."),
+                hint=None,
                 obj=field,
-                id='E030',
+                id='fields.E300',
             ),
         ]
         self.assertEqual(errors, expected)
@@ -53,13 +51,11 @@ class RelativeFieldTests(IsolatedModelsTestCase):
         errors = field.check(from_model=Model)
         expected = [
             Error(
-                ('The field has a relation with model Rel2, '
-                 'which has either not been installed or is abstract.'),
-                hint=('Ensure that you did not misspell the model name and '
-                      'the model is not abstract. Does your INSTALLED_APPS '
-                      'setting contain the app where Rel2 is defined?'),
+                ("Field defines a relation with model 'Rel2', "
+                 "which is either not installed, or is abstract."),
+                hint=None,
                 obj=field,
-                id='E030',
+                id='fields.E300',
             ),
         ]
         self.assertEqual(errors, expected)
@@ -83,15 +79,14 @@ class RelativeFieldTests(IsolatedModelsTestCase):
         errors = field.check(from_model=Group)
         expected = [
             Error(
-                ('The model is used as an intermediary model by '
-                 'invalid_models_tests.Group.field, but it has more than one '
-                 'foreign key to Person, '
-                 'which is ambiguous and is not permitted.'),
+                ("The model is used as an intermediate model by "
+                 "'invalid_models_tests.Group.field', but it has more than one "
+                 "foreign key to 'Person', which is ambiguous."),
                 hint=('If you want to create a recursive relationship, use '
                       'ForeignKey("self", symmetrical=False, '
                       'through="AmbiguousRelationship").'),
                 obj=field,
-                id='E027',
+                id='fields.E335',
             ),
         ]
         self.assertEqual(errors, expected)
@@ -116,12 +111,12 @@ class RelativeFieldTests(IsolatedModelsTestCase):
         errors = field.check(from_model=Group)
         expected = [
             Error(
-                ('The model is used as an intermediary model by '
-                 'invalid_models_tests.Group.members, but it misses '
-                 'a foreign key to Group or Person.'),
+                ("The model is used as an intermediate model by "
+                 "'invalid_models_tests.Group.members', but it does not "
+                 "have a foreign key to 'Group' or 'Person'."),
                 hint=None,
                 obj=InvalidRelationship,
-                id='E028',
+                id='fields.E336',
             ),
         ]
         self.assertEqual(errors, expected)
@@ -142,12 +137,12 @@ class RelativeFieldTests(IsolatedModelsTestCase):
         errors = field.check(from_model=Group)
         expected = [
             Error(
-                ('The model is used as an intermediary model by '
-                 'invalid_models_tests.Group.members, but it misses '
-                 'a foreign key to Group or Person.'),
+                ("The model is used as an intermediate model by "
+                 "'invalid_models_tests.Group.members', but it does not have "
+                 "a foreign key to 'Group' or 'Person'."),
                 hint=None,
                 obj=InvalidRelationship,
-                id='E028',
+                id='fields.E336',
             ),
         ]
         self.assertEqual(errors, expected)
@@ -164,13 +159,11 @@ class RelativeFieldTests(IsolatedModelsTestCase):
         errors = field.check(from_model=Group)
         expected = [
             Error(
-                ('The field specifies a many-to-many relation through model '
-                 'MissingM2MModel, which has not been installed.'),
-                hint=('Ensure that you did not misspell the model name and '
-                      'the model is not abstract. Does your INSTALLED_APPS '
-                      'setting contain the app where MissingM2MModel is defined?'),
+                ("Field specifies a many-to-many relation through model "
+                 "'MissingM2MModel', which has not been installed."),
+                hint=None,
                 obj=field,
-                id='E023',
+                id='fields.E331',
             ),
         ]
         self.assertEqual(errors, expected)
@@ -191,7 +184,7 @@ class RelativeFieldTests(IsolatedModelsTestCase):
                 'Many-to-many fields with intermediate tables must not be symmetrical.',
                 hint=None,
                 obj=field,
-                id='E024',
+                id='fields.E332',
             ),
         ]
         self.assertEqual(errors, expected)
@@ -210,13 +203,12 @@ class RelativeFieldTests(IsolatedModelsTestCase):
         errors = field.check(from_model=Person)
         expected = [
             Error(
-                ('The model is used as an intermediary model by '
-                 'invalid_models_tests.Person.friends, but it has more than two '
-                 'foreign keys to Person, which is ambiguous and '
-                 'is not permitted.'),
+                ("The model is used as an intermediate model by "
+                 "'invalid_models_tests.Person.friends', but it has more than two "
+                 "foreign keys to 'Person', which is ambiguous."),
                 hint=None,
                 obj=InvalidRelationship,
-                id='E025',
+                id='fields.E333',
             ),
         ]
         self.assertEqual(errors, expected)
@@ -238,7 +230,7 @@ class RelativeFieldTests(IsolatedModelsTestCase):
                 'Many-to-many fields with intermediate tables must not be symmetrical.',
                 hint=None,
                 obj=field,
-                id='E024',
+                id='fields.E332',
             ),
         ]
         self.assertEqual(errors, expected)
@@ -255,13 +247,11 @@ class RelativeFieldTests(IsolatedModelsTestCase):
         errors = field.check()
         expected = [
             Error(
-                ('The field has a relation with model AbstractModel, '
-                 'which has either not been installed or is abstract.'),
-                hint=('Ensure that you did not misspell the model name and '
-                      'the model is not abstract. Does your INSTALLED_APPS '
-                      'setting contain the app where AbstractModel is defined?'),
+                ("Field defines a relation with model 'AbstractModel', "
+                 "which is either not installed, or is abstract."),
+                hint=None,
                 obj=field,
-                id='E030',
+                id='fields.E300',
             ),
         ]
         self.assertEqual(errors, expected)
@@ -278,13 +268,11 @@ class RelativeFieldTests(IsolatedModelsTestCase):
         errors = field.check(from_model=Model)
         expected = [
             Error(
-                ('The field has a relation with model AbstractModel, '
-                 'which has either not been installed or is abstract.'),
-                hint=('Ensure that you did not misspell the model name and '
-                      'the model is not abstract. Does your INSTALLED_APPS '
-                      'setting contain the app where AbstractModel is defined?'),
+                ("Field defines a relation with model 'AbstractModel', "
+                 "which is either not installed, or is abstract."),
+                hint=None,
                 obj=field,
-                id='E030',
+                id='fields.E300',
             ),
         ]
         self.assertEqual(errors, expected)
@@ -300,10 +288,10 @@ class RelativeFieldTests(IsolatedModelsTestCase):
         errors = field.check(from_model=Group)
         expected = [
             Error(
-                'ManyToManyFields must not be unique.',
+                'ManyToManyFields cannot be unique.',
                 hint=None,
                 obj=field,
-                id='E022',
+                id='fields.E330',
             ),
         ]
         self.assertEqual(errors, expected)
@@ -319,10 +307,10 @@ class RelativeFieldTests(IsolatedModelsTestCase):
         errors = field.check()
         expected = [
             Error(
-                'Target.bad must have unique=True because it is referenced by a foreign key.',
+                "'Target.bad' must set unique=True because it is referenced by a foreign key.",
                 hint=None,
                 obj=field,
-                id='E019',
+                id='fields.E311',
             ),
         ]
         self.assertEqual(errors, expected)
@@ -338,10 +326,10 @@ class RelativeFieldTests(IsolatedModelsTestCase):
         errors = field.check()
         expected = [
             Error(
-                'Target.bad must have unique=True because it is referenced by a foreign key.',
+                "'Target.bad' must set unique=True because it is referenced by a foreign key.",
                 hint=None,
                 obj=field,
-                id='E019',
+                id='fields.E311',
             ),
         ]
         self.assertEqual(errors, expected)
@@ -364,12 +352,11 @@ class RelativeFieldTests(IsolatedModelsTestCase):
         errors = field.check()
         expected = [
             Error(
-                ('No unique=True constraint on field combination '
-                 '"country_id,city_id" under model Person.'),
-                hint=('Set unique=True argument on any of the fields '
-                      '"country_id,city_id" under model Person.'),
+                ("None of the fields 'country_id', 'city_id' on model 'Person' "
+                 "have a unique=True constraint."),
+                hint=None,
                 obj=field,
-                id='E018',
+                id='fields.E310',
             )
         ]
         self.assertEqual(errors, expected)
@@ -386,10 +373,10 @@ class RelativeFieldTests(IsolatedModelsTestCase):
         errors = field.check()
         expected = [
             Error(
-                'The field specifies on_delete=SET_NULL, but cannot be null.',
-                hint='Set null=True argument on the field.',
+                'Field specifies on_delete=SET_NULL, but cannot be null.',
+                hint='Set null=True argument on the field, or change the on_delete rule.',
                 obj=field,
-                id='E020',
+                id='fields.E320',
             ),
         ]
         self.assertEqual(errors, expected)
@@ -406,10 +393,10 @@ class RelativeFieldTests(IsolatedModelsTestCase):
         errors = field.check()
         expected = [
             Error(
-                'The field specifies on_delete=SET_DEFAULT, but has no default value.',
-                hint=None,
+                'Field specifies on_delete=SET_DEFAULT, but has no default value.',
+                hint='Set a default value, or change the on_delete rule.',
                 obj=field,
-                id='E021',
+                id='fields.E321',
             ),
         ]
         self.assertEqual(errors, expected)
@@ -424,9 +411,9 @@ class RelativeFieldTests(IsolatedModelsTestCase):
         expected = [
             Error(
                 'Primary keys must not have null=True.',
-                hint='Set null=False on the field or remove primary_key=True argument.',
+                hint='Set null=False on the field, or remove primary_key=True argument.',
                 obj=field,
-                id='E036',
+                id='fields.E007',
             ),
         ]
         self.assertEqual(errors, expected)
@@ -489,10 +476,10 @@ class RelativeFieldTests(IsolatedModelsTestCase):
         ]
 
         expected_error = Error(
-            ('The field defines a relation with the model '
-             'invalid_models_tests.SwappedModel, which has been swapped out.'),
-            hint='Update the relation to point at settings.TEST_SWAPPED_MODEL',
-            id='E029',
+            ("Field defines a relation with the model "
+             "'invalid_models_tests.SwappedModel', which has been swapped out."),
+            hint="Update the relation to point at 'settings.TEST_SWAPPED_MODEL'.",
+            id='fields.E301',
         )
 
         for field in fields:
@@ -546,12 +533,12 @@ class AccessorClashTests(IsolatedModelsTestCase):
         errors = Model.check()
         expected = [
             Error(
-                'Accessor for field Model.rel clashes with field Target.model_set.',
-                hint=('Rename field Target.model_set or add/change '
-                      'a related_name argument to the definition '
-                      'for field Model.rel.'),
+                "Reverse accessor for 'Model.rel' clashes with field name 'Target.model_set'.",
+                hint=("Rename field 'Target.model_set', or add/change "
+                      "a related_name argument to the definition "
+                      "for field 'Model.rel'."),
                 obj=Model._meta.get_field('rel'),
-                id='E014',
+                id='fields.E302',
             ),
         ]
         self.assertEqual(errors, expected)
@@ -567,18 +554,18 @@ class AccessorClashTests(IsolatedModelsTestCase):
         errors = Model.check()
         expected = [
             Error(
-                'Clash between accessors for Model.foreign and Model.m2m.',
-                hint=('Add or change a related_name argument to the definition '
-                      'for Model.foreign or Model.m2m.'),
+                "Reverse accessor for 'Model.foreign' clashes with reverse accessor for 'Model.m2m'.",
+                hint=("Add or change a related_name argument to the definition "
+                      "for 'Model.foreign' or 'Model.m2m'."),
                 obj=Model._meta.get_field('foreign'),
-                id='E016',
+                id='fields.E304',
             ),
             Error(
-                'Clash between accessors for Model.m2m and Model.foreign.',
-                hint=('Add or change a related_name argument to the definition '
-                      'for Model.m2m or Model.foreign.'),
+                "Reverse accessor for 'Model.m2m' clashes with reverse accessor for 'Model.foreign'.",
+                hint=("Add or change a related_name argument to the definition "
+                      "for 'Model.m2m' or 'Model.foreign'."),
                 obj=Model._meta.get_field('m2m'),
-                id='E016',
+                id='fields.E304',
             ),
         ]
         self.assertEqual(errors, expected)
@@ -602,12 +589,12 @@ class AccessorClashTests(IsolatedModelsTestCase):
         errors = Model.check()
         expected = [
             Error(
-                'Accessor for field Model.children clashes with field Child.m2m_clash.',
-                hint=('Rename field Child.m2m_clash or add/change '
-                      'a related_name argument to the definition '
-                      'for field Model.children.'),
+                "Reverse accessor for 'Model.children' clashes with field name 'Child.m2m_clash'.",
+                hint=("Rename field 'Child.m2m_clash', or add/change "
+                      "a related_name argument to the definition "
+                      "for field 'Model.children'."),
                 obj=Model._meta.get_field('children'),
-                id='E014',
+                id='fields.E302',
             )
         ]
         self.assertEqual(errors, expected)
@@ -658,12 +645,12 @@ class ReverseQueryNameClashTests(IsolatedModelsTestCase):
         errors = Model.check()
         expected = [
             Error(
-                'Reverse query name for field Model.rel clashes with field Target.model.',
-                hint=('Rename field Target.model or add/change '
-                      'a related_name argument to the definition '
-                      'for field Model.rel.'),
+                "Reverse query name for 'Model.rel' clashes with field name 'Target.model'.",
+                hint=("Rename field 'Target.model', or add/change "
+                      "a related_name argument to the definition "
+                      "for field 'Model.rel'."),
                 obj=Model._meta.get_field('rel'),
-                id='E015',
+                id='fields.E303',
             ),
         ]
         self.assertEqual(errors, expected)
@@ -714,20 +701,20 @@ class ExplicitRelatedNameClashTests(IsolatedModelsTestCase):
         errors = Model.check()
         expected = [
             Error(
-                'Accessor for field Model.rel clashes with field Target.clash.',
-                hint=('Rename field Target.clash or add/change '
-                      'a related_name argument to the definition '
-                      'for field Model.rel.'),
+                "Reverse accessor for 'Model.rel' clashes with field name 'Target.clash'.",
+                hint=("Rename field 'Target.clash', or add/change "
+                      "a related_name argument to the definition "
+                      "for field 'Model.rel'."),
                 obj=Model._meta.get_field('rel'),
-                id='E014',
+                id='fields.E302',
             ),
             Error(
-                'Reverse query name for field Model.rel clashes with field Target.clash.',
-                hint=('Rename field Target.clash or add/change '
-                      'a related_name argument to the definition '
-                      'for field Model.rel.'),
+                "Reverse query name for 'Model.rel' clashes with field name 'Target.clash'.",
+                hint=("Rename field 'Target.clash', or add/change "
+                      "a related_name argument to the definition "
+                      "for field 'Model.rel'."),
                 obj=Model._meta.get_field('rel'),
-                id='E015',
+                id='fields.E303',
             ),
         ]
         self.assertEqual(errors, expected)
@@ -784,11 +771,11 @@ class ExplicitRelatedQueryNameClashTests(IsolatedModelsTestCase):
         errors = Model.check()
         expected = [
             Error(
-                'Reverse query name for field Model.rel clashes with field Target.clash.',
-                hint=('Rename field Target.clash or add/change a related_name '
-                      'argument to the definition for field Model.rel.'),
+                "Reverse query name for 'Model.rel' clashes with field name 'Target.clash'.",
+                hint=("Rename field 'Target.clash', or add/change a related_name "
+                      "argument to the definition for field 'Model.rel'."),
                 obj=Model._meta.get_field('rel'),
-                id='E015',
+                id='fields.E303',
             ),
         ]
         self.assertEqual(errors, expected)
@@ -804,18 +791,18 @@ class SelfReferentialM2MClashTests(IsolatedModelsTestCase):
         errors = Model.check()
         expected = [
             Error(
-                'Clash between accessors for Model.first_m2m and Model.second_m2m.',
-                hint=('Add or change a related_name argument to the definition '
-                      'for Model.first_m2m or Model.second_m2m.'),
+                "Reverse accessor for 'Model.first_m2m' clashes with reverse accessor for 'Model.second_m2m'.",
+                hint=("Add or change a related_name argument to the definition "
+                      "for 'Model.first_m2m' or 'Model.second_m2m'."),
                 obj=Model._meta.get_field('first_m2m'),
-                id='E016',
+                id='fields.E304',
             ),
             Error(
-                'Clash between accessors for Model.second_m2m and Model.first_m2m.',
-                hint=('Add or change a related_name argument to the definition '
-                      'for Model.second_m2m or Model.first_m2m.'),
+                "Reverse accessor for 'Model.second_m2m' clashes with reverse accessor for 'Model.first_m2m'.",
+                hint=("Add or change a related_name argument to the definition "
+                      "for 'Model.second_m2m' or 'Model.first_m2m'."),
                 obj=Model._meta.get_field('second_m2m'),
-                id='E016',
+                id='fields.E304',
             ),
         ]
         self.assertEqual(errors, expected)
@@ -827,12 +814,12 @@ class SelfReferentialM2MClashTests(IsolatedModelsTestCase):
         errors = Model.check()
         expected = [
             Error(
-                'Accessor for field Model.model_set clashes with field Model.model_set.',
-                hint=('Rename field Model.model_set or add/change '
-                     'a related_name argument to the definition '
-                     'for field Model.model_set.'),
+                "Reverse accessor for 'Model.model_set' clashes with field name 'Model.model_set'.",
+                hint=("Rename field 'Model.model_set', or add/change "
+                      "a related_name argument to the definition "
+                      "for field 'Model.model_set'."),
                 obj=Model._meta.get_field('model_set'),
-                id='E014',
+                id='fields.E302',
             ),
         ]
         self.assertEqual(errors, expected)
@@ -844,11 +831,11 @@ class SelfReferentialM2MClashTests(IsolatedModelsTestCase):
         errors = Model.check()
         expected = [
             Error(
-                'Reverse query name for field Model.model clashes with field Model.model.',
-                hint=('Rename field Model.model or add/change a related_name '
-                      'argument to the definition for field Model.model.'),
+                "Reverse query name for 'Model.model' clashes with field name 'Model.model'.",
+                hint=("Rename field 'Model.model', or add/change a related_name "
+                      "argument to the definition for field 'Model.model'."),
                 obj=Model._meta.get_field('model'),
-                id='E015',
+                id='fields.E303',
             ),
         ]
         self.assertEqual(errors, expected)
@@ -862,18 +849,18 @@ class SelfReferentialM2MClashTests(IsolatedModelsTestCase):
         errors = Model.check()
         expected = [
             Error(
-                'Accessor for field Model.m2m clashes with field Model.clash.',
-                hint=('Rename field Model.clash or add/change a related_name '
-                      'argument to the definition for field Model.m2m.'),
+                "Reverse accessor for 'Model.m2m' clashes with field name 'Model.clash'.",
+                hint=("Rename field 'Model.clash', or add/change a related_name "
+                      "argument to the definition for field 'Model.m2m'."),
                 obj=Model._meta.get_field('m2m'),
-                id='E014',
+                id='fields.E302',
             ),
             Error(
-                'Reverse query name for field Model.m2m clashes with field Model.clash.',
-                hint=('Rename field Model.clash or add/change a related_name '
-                      'argument to the definition for field Model.m2m.'),
+                "Reverse query name for 'Model.m2m' clashes with field name 'Model.clash'.",
+                hint=("Rename field 'Model.clash', or add/change a related_name "
+                      "argument to the definition for field 'Model.m2m'."),
                 obj=Model._meta.get_field('m2m'),
-                id='E015',
+                id='fields.E303',
             ),
         ]
         self.assertEqual(errors, expected)
@@ -898,12 +885,12 @@ class SelfReferentialFKClashTests(IsolatedModelsTestCase):
         errors = Model.check()
         expected = [
             Error(
-                'Accessor for field Model.model_set clashes with field Model.model_set.',
-                hint=('Rename field Model.model_set or add/change '
-                      'a related_name argument to the definition '
-                      'for field Model.model_set.'),
+                "Reverse accessor for 'Model.model_set' clashes with field name 'Model.model_set'.",
+                hint=("Rename field 'Model.model_set', or add/change "
+                      "a related_name argument to the definition "
+                      "for field 'Model.model_set'."),
                 obj=Model._meta.get_field('model_set'),
-                id='E014',
+                id='fields.E302',
             ),
         ]
         self.assertEqual(errors, expected)
@@ -915,12 +902,12 @@ class SelfReferentialFKClashTests(IsolatedModelsTestCase):
         errors = Model.check()
         expected = [
             Error(
-                'Reverse query name for field Model.model clashes with field Model.model.',
-                hint=('Rename field Model.model or add/change '
-                      'a related_name argument to the definition '
-                      'for field Model.model.'),
+                "Reverse query name for 'Model.model' clashes with field name 'Model.model'.",
+                hint=("Rename field 'Model.model', or add/change "
+                      "a related_name argument to the definition "
+                      "for field 'Model.model'."),
                 obj=Model._meta.get_field('model'),
-                id='E015',
+                id='fields.E303',
             ),
         ]
         self.assertEqual(errors, expected)
@@ -933,20 +920,20 @@ class SelfReferentialFKClashTests(IsolatedModelsTestCase):
         errors = Model.check()
         expected = [
             Error(
-                'Accessor for field Model.foreign clashes with field Model.clash.',
-                hint=('Rename field Model.clash or add/change '
-                      'a related_name argument to the definition '
-                      'for field Model.foreign.'),
+                "Reverse accessor for 'Model.foreign' clashes with field name 'Model.clash'.",
+                hint=("Rename field 'Model.clash', or add/change "
+                      "a related_name argument to the definition "
+                      "for field 'Model.foreign'."),
                 obj=Model._meta.get_field('foreign'),
-                id='E014',
+                id='fields.E302',
             ),
             Error(
-                'Reverse query name for field Model.foreign clashes with field Model.clash.',
-                hint=('Rename field Model.clash or add/change '
-                      'a related_name argument to the definition '
-                      'for field Model.foreign.'),
+                "Reverse query name for 'Model.foreign' clashes with field name 'Model.clash'.",
+                hint=("Rename field 'Model.clash', or add/change "
+                      "a related_name argument to the definition "
+                      "for field 'Model.foreign'."),
                 obj=Model._meta.get_field('foreign'),
-                id='E015',
+                id='fields.E303',
             ),
         ]
         self.assertEqual(errors, expected)
@@ -976,91 +963,91 @@ class ComplexClashTests(IsolatedModelsTestCase):
         errors = Model.check()
         expected = [
             Error(
-                'Accessor for field Model.foreign_1 clashes with field Target.id.',
-                hint=('Rename field Target.id or add/change a related_name '
-                      'argument to the definition for field Model.foreign_1.'),
+                "Reverse accessor for 'Model.foreign_1' clashes with field name 'Target.id'.",
+                hint=("Rename field 'Target.id', or add/change a related_name "
+                      "argument to the definition for field 'Model.foreign_1'."),
                 obj=Model._meta.get_field('foreign_1'),
-                id='E014',
+                id='fields.E302',
             ),
             Error(
-                'Reverse query name for field Model.foreign_1 clashes with field Target.id.',
-                hint=('Rename field Target.id or add/change a related_name '
-                      'argument to the definition for field Model.foreign_1.'),
+                "Reverse query name for 'Model.foreign_1' clashes with field name 'Target.id'.",
+                hint=("Rename field 'Target.id', or add/change a related_name "
+                      "argument to the definition for field 'Model.foreign_1'."),
                 obj=Model._meta.get_field('foreign_1'),
-                id='E015',
+                id='fields.E303',
             ),
             Error(
-                'Clash between accessors for Model.foreign_1 and Model.m2m_1.',
-                hint=('Add or change a related_name argument to '
-                      'the definition for Model.foreign_1 or Model.m2m_1.'),
+                "Reverse accessor for 'Model.foreign_1' clashes with reverse accessor for 'Model.m2m_1'.",
+                hint=("Add or change a related_name argument to "
+                      "the definition for 'Model.foreign_1' or 'Model.m2m_1'."),
                 obj=Model._meta.get_field('foreign_1'),
-                id='E016',
+                id='fields.E304',
             ),
             Error(
-                'Clash between reverse query names for Model.foreign_1 and Model.m2m_1.',
-                hint=('Add or change a related_name argument to '
-                      'the definition for Model.foreign_1 or Model.m2m_1.'),
+                "Reverse query name for 'Model.foreign_1' clashes with reverse query name for 'Model.m2m_1'.",
+                hint=("Add or change a related_name argument to "
+                      "the definition for 'Model.foreign_1' or 'Model.m2m_1'."),
                 obj=Model._meta.get_field('foreign_1'),
-                id='E017',
+                id='fields.E305',
             ),
 
             Error(
-                'Clash between accessors for Model.foreign_2 and Model.m2m_2.',
-                hint=('Add or change a related_name argument '
-                      'to the definition for Model.foreign_2 or Model.m2m_2.'),
+                "Reverse accessor for 'Model.foreign_2' clashes with reverse accessor for 'Model.m2m_2'.",
+                hint=("Add or change a related_name argument "
+                      "to the definition for 'Model.foreign_2' or 'Model.m2m_2'."),
                 obj=Model._meta.get_field('foreign_2'),
-                id='E016',
+                id='fields.E304',
             ),
             Error(
-                'Clash between reverse query names for Model.foreign_2 and Model.m2m_2.',
-                hint=('Add or change a related_name argument to '
-                      'the definition for Model.foreign_2 or Model.m2m_2.'),
+                "Reverse query name for 'Model.foreign_2' clashes with reverse query name for 'Model.m2m_2'.",
+                hint=("Add or change a related_name argument to "
+                      "the definition for 'Model.foreign_2' or 'Model.m2m_2'."),
                 obj=Model._meta.get_field('foreign_2'),
-                id='E017',
+                id='fields.E305',
             ),
 
             Error(
-                'Accessor for field Model.m2m_1 clashes with field Target.id.',
-                hint=('Rename field Target.id or add/change a related_name '
-                      'argument to the definition for field Model.m2m_1.'),
+                "Reverse accessor for 'Model.m2m_1' clashes with field name 'Target.id'.",
+                hint=("Rename field 'Target.id', or add/change a related_name "
+                      "argument to the definition for field 'Model.m2m_1'."),
                 obj=Model._meta.get_field('m2m_1'),
-                id='E014',
+                id='fields.E302',
             ),
             Error(
-                'Reverse query name for field Model.m2m_1 clashes with field Target.id.',
-                hint=('Rename field Target.id or add/change a related_name '
-                      'argument to the definition for field Model.m2m_1.'),
+                "Reverse query name for 'Model.m2m_1' clashes with field name 'Target.id'.",
+                hint=("Rename field 'Target.id', or add/change a related_name "
+                      "argument to the definition for field 'Model.m2m_1'."),
                 obj=Model._meta.get_field('m2m_1'),
-                id='E015',
+                id='fields.E303',
             ),
             Error(
-                'Clash between accessors for Model.m2m_1 and Model.foreign_1.',
-                hint=('Add or change a related_name argument to the definition '
-                      'for Model.m2m_1 or Model.foreign_1.'),
+                "Reverse accessor for 'Model.m2m_1' clashes with reverse accessor for 'Model.foreign_1'.",
+                hint=("Add or change a related_name argument to the definition "
+                      "for 'Model.m2m_1' or 'Model.foreign_1'."),
                 obj=Model._meta.get_field('m2m_1'),
-                id='E016',
+                id='fields.E304',
             ),
             Error(
-                'Clash between reverse query names for Model.m2m_1 and Model.foreign_1.',
-                hint=('Add or change a related_name argument to '
-                      'the definition for Model.m2m_1 or Model.foreign_1.'),
+                "Reverse query name for 'Model.m2m_1' clashes with reverse query name for 'Model.foreign_1'.",
+                hint=("Add or change a related_name argument to "
+                      "the definition for 'Model.m2m_1' or 'Model.foreign_1'."),
                 obj=Model._meta.get_field('m2m_1'),
-                id='E017',
+                id='fields.E305',
             ),
 
             Error(
-                'Clash between accessors for Model.m2m_2 and Model.foreign_2.',
-                hint=('Add or change a related_name argument to the definition '
-                      'for Model.m2m_2 or Model.foreign_2.'),
+                "Reverse accessor for 'Model.m2m_2' clashes with reverse accessor for 'Model.foreign_2'.",
+                hint=("Add or change a related_name argument to the definition "
+                      "for 'Model.m2m_2' or 'Model.foreign_2'."),
                 obj=Model._meta.get_field('m2m_2'),
-                id='E016',
+                id='fields.E304',
             ),
             Error(
-                'Clash between reverse query names for Model.m2m_2 and Model.foreign_2.',
-                hint=('Add or change a related_name argument to the definition '
-                      'for Model.m2m_2 or Model.foreign_2.'),
+                "Reverse query name for 'Model.m2m_2' clashes with reverse query name for 'Model.foreign_2'.",
+                hint=("Add or change a related_name argument to the definition "
+                      "for 'Model.m2m_2' or 'Model.foreign_2'."),
                 obj=Model._meta.get_field('m2m_2'),
-                id='E017',
+                id='fields.E305',
             ),
         ]
         self.assertEqual(errors, expected)

tests/model_validation/tests.py

@@ -37,7 +37,7 @@ class ModelValidationTest(TestCase):
                 "sender, which has not been installed.",
                 hint=None,
                 obj='model_validation.tests',
-                id='E014',
+                id='signals.E001',
             ),
             Error(
                 "An instance of the `OnPostInit` class was connected to "
@@ -45,7 +45,7 @@ class ModelValidationTest(TestCase):
                 "'missing-app.Model' sender, which has not been installed.",
                 hint=None,
                 obj='model_validation.tests',
-                id='E014',
+                id='signals.E001',
             )
         ]
         self.assertEqual(errors, expected)