Fixed #28192 -- Required passing optional form field args as keyword args.

7 files changed, 66 insertions, 62 deletions

diff --git a/django/contrib/postgres/forms/array.py b/django/contrib/postgres/forms/array.py
index 97e4346f60..6b3b217810 100644
--- a/django/contrib/postgres/forms/array.py
+++ b/django/contrib/postgres/forms/array.py
@@ -16,10 +16,10 @@ class SimpleArrayField(forms.CharField):
         'item_invalid': _('Item %(nth)s in the array did not validate: '),
     }
 
-    def __init__(self, base_field, delimiter=',', max_length=None, min_length=None, *args, **kwargs):
+    def __init__(self, base_field, *, delimiter=',', max_length=None, min_length=None, **kwargs):
         self.base_field = base_field
         self.delimiter = delimiter
-        super().__init__(*args, **kwargs)
+        super().__init__(**kwargs)
         if min_length is not None:
             self.min_length = min_length
             self.validators.append(ArrayMinLengthValidator(int(min_length)))
@@ -156,7 +156,7 @@ class SplitArrayField(forms.Field):
         'item_invalid': _('Item %(nth)s in the array did not validate: '),
     }
 
-    def __init__(self, base_field, size, remove_trailing_nulls=False, **kwargs):
+    def __init__(self, base_field, size, *, remove_trailing_nulls=False, **kwargs):
         self.base_field = base_field
         self.size = size
         self.remove_trailing_nulls = remove_trailing_nulls
diff --git a/django/forms/fields.py b/django/forms/fields.py
index f621aa65da..1bc6953561 100644
--- a/django/forms/fields.py
+++ b/django/forms/fields.py
@@ -53,7 +53,7 @@ class Field:
     }
     empty_values = list(validators.EMPTY_VALUES)
 
-    def __init__(self, required=True, widget=None, label=None, initial=None,
+    def __init__(self, *, required=True, widget=None, label=None, initial=None,
                  help_text='', error_messages=None, show_hidden_initial=False,
                  validators=(), localize=False, disabled=False, label_suffix=None):
         # required -- Boolean that specifies whether the field is required.
@@ -205,12 +205,12 @@ class Field:
 
 
 class CharField(Field):
-    def __init__(self, max_length=None, min_length=None, strip=True, empty_value='', *args, **kwargs):
+    def __init__(self, *, max_length=None, min_length=None, strip=True, empty_value='', **kwargs):
         self.max_length = max_length
         self.min_length = min_length
         self.strip = strip
         self.empty_value = empty_value
-        super().__init__(*args, **kwargs)
+        super().__init__(**kwargs)
         if min_length is not None:
             self.validators.append(validators.MinLengthValidator(int(min_length)))
         if max_length is not None:
@@ -243,12 +243,12 @@ class IntegerField(Field):
     }
     re_decimal = re.compile(r'\.0*\s*$')
 
-    def __init__(self, max_value=None, min_value=None, *args, **kwargs):
+    def __init__(self, *, max_value=None, min_value=None, **kwargs):
         self.max_value, self.min_value = max_value, min_value
         if kwargs.get('localize') and self.widget == NumberInput:
             # Localized number input is not well supported on most browsers
             kwargs.setdefault('widget', super().widget)
-        super().__init__(*args, **kwargs)
+        super().__init__(**kwargs)
 
         if max_value is not None:
             self.validators.append(validators.MaxValueValidator(max_value))
@@ -324,9 +324,9 @@ class DecimalField(IntegerField):
         'invalid': _('Enter a number.'),
     }
 
-    def __init__(self, max_value=None, min_value=None, max_digits=None, decimal_places=None, *args, **kwargs):
+    def __init__(self, *, max_value=None, min_value=None, max_digits=None, decimal_places=None, **kwargs):
         self.max_digits, self.decimal_places = max_digits, decimal_places
-        super().__init__(max_value, min_value, *args, **kwargs)
+        super().__init__(max_value=max_value, min_value=min_value, **kwargs)
         self.validators.append(validators.DecimalValidator(max_digits, decimal_places))
 
     def to_python(self, value):
@@ -372,8 +372,8 @@ class DecimalField(IntegerField):
 
 class BaseTemporalField(Field):
 
-    def __init__(self, input_formats=None, *args, **kwargs):
-        super().__init__(*args, **kwargs)
+    def __init__(self, *, input_formats=None, **kwargs):
+        super().__init__(**kwargs)
         if input_formats is not None:
             self.input_formats = input_formats
 
@@ -490,12 +490,12 @@ class DurationField(Field):
 
 
 class RegexField(CharField):
-    def __init__(self, regex, max_length=None, min_length=None, *args, **kwargs):
+    def __init__(self, regex, **kwargs):
         """
         regex can be either a string or a compiled regular expression object.
         """
         kwargs.setdefault('strip', False)
-        super().__init__(max_length, min_length, *args, **kwargs)
+        super().__init__(**kwargs)
         self._set_regex(regex)
 
     def _get_regex(self):
@@ -517,8 +517,8 @@ class EmailField(CharField):
     widget = EmailInput
     default_validators = [validators.validate_email]
 
-    def __init__(self, *args, **kwargs):
-        super().__init__(*args, strip=True, **kwargs)
+    def __init__(self, **kwargs):
+        super().__init__(strip=True, **kwargs)
 
 
 class FileField(Field):
@@ -534,10 +534,10 @@ class FileField(Field):
         'contradiction': _('Please either submit a file or check the clear checkbox, not both.')
     }
 
-    def __init__(self, *args, max_length=None, allow_empty_file=False, **kwargs):
+    def __init__(self, *, max_length=None, allow_empty_file=False, **kwargs):
         self.max_length = max_length
         self.allow_empty_file = allow_empty_file
-        super().__init__(*args, **kwargs)
+        super().__init__(**kwargs)
 
     def to_python(self, data):
         if data in self.empty_values:
@@ -650,8 +650,8 @@ class URLField(CharField):
     }
     default_validators = [validators.URLValidator()]
 
-    def __init__(self, *args, **kwargs):
-        super().__init__(*args, strip=True, **kwargs)
+    def __init__(self, **kwargs):
+        super().__init__(strip=True, **kwargs)
 
     def to_python(self, value):
 
@@ -751,12 +751,8 @@ class ChoiceField(Field):
         'invalid_choice': _('Select a valid choice. %(value)s is not one of the available choices.'),
     }
 
-    def __init__(self, choices=(), required=True, widget=None, label=None,
-                 initial=None, help_text='', *args, **kwargs):
-        super().__init__(
-            required=required, widget=widget, label=label, initial=initial,
-            help_text=help_text, *args, **kwargs
-        )
+    def __init__(self, *, choices=(), **kwargs):
+        super().__init__(**kwargs)
         self.choices = choices
 
     def __deepcopy__(self, memo):
@@ -812,10 +808,10 @@ class ChoiceField(Field):
 
 
 class TypedChoiceField(ChoiceField):
-    def __init__(self, *args, coerce=lambda val: val, empty_value='', **kwargs):
+    def __init__(self, *, coerce=lambda val: val, empty_value='', **kwargs):
         self.coerce = coerce
         self.empty_value = empty_value
-        super().__init__(*args, **kwargs)
+        super().__init__(**kwargs)
 
     def _coerce(self, value):
         """
@@ -879,10 +875,10 @@ class MultipleChoiceField(ChoiceField):
 
 
 class TypedMultipleChoiceField(MultipleChoiceField):
-    def __init__(self, *args, coerce=lambda val: val, **kwargs):
+    def __init__(self, *, coerce=lambda val: val, **kwargs):
         self.coerce = coerce
         self.empty_value = kwargs.pop('empty_value', [])
-        super().__init__(*args, **kwargs)
+        super().__init__(**kwargs)
 
     def _coerce(self, value):
         """
@@ -918,8 +914,8 @@ class ComboField(Field):
     """
     A Field whose clean() method calls multiple Field clean() methods.
     """
-    def __init__(self, fields, *args, **kwargs):
-        super().__init__(*args, **kwargs)
+    def __init__(self, fields, **kwargs):
+        super().__init__(**kwargs)
         # Set 'required' to False on the individual fields, because the
         # required validation will be handled by ComboField, not by those
         # individual fields.
@@ -960,9 +956,9 @@ class MultiValueField(Field):
         'incomplete': _('Enter a complete value.'),
     }
 
-    def __init__(self, fields, *args, require_all_fields=True, **kwargs):
+    def __init__(self, fields, *, require_all_fields=True, **kwargs):
         self.require_all_fields = require_all_fields
-        super().__init__(*args, **kwargs)
+        super().__init__(**kwargs)
         for f in fields:
             f.error_messages.setdefault('incomplete',
                                         self.error_messages['incomplete'])
@@ -1061,15 +1057,11 @@ class MultiValueField(Field):
 
 
 class FilePathField(ChoiceField):
-    def __init__(self, path, match=None, recursive=False, allow_files=True,
-                 allow_folders=False, required=True, widget=None, label=None,
-                 initial=None, help_text='', *args, **kwargs):
+    def __init__(self, path, *, match=None, recursive=False, allow_files=True,
+                 allow_folders=False, **kwargs):
         self.path, self.match, self.recursive = path, match, recursive
         self.allow_files, self.allow_folders = allow_files, allow_folders
-        super().__init__(
-            choices=(), required=required, widget=widget, label=label,
-            initial=initial, help_text=help_text, *args, **kwargs
-        )
+        super().__init__(choices=(), **kwargs)
 
         if self.required:
             self.choices = []
@@ -1117,7 +1109,7 @@ class SplitDateTimeField(MultiValueField):
         'invalid_time': _('Enter a valid time.'),
     }
 
-    def __init__(self, input_date_formats=None, input_time_formats=None, *args, **kwargs):
+    def __init__(self, *, input_date_formats=None, input_time_formats=None, **kwargs):
         errors = self.default_error_messages.copy()
         if 'error_messages' in kwargs:
             errors.update(kwargs['error_messages'])
@@ -1130,7 +1122,7 @@ class SplitDateTimeField(MultiValueField):
                       error_messages={'invalid': errors['invalid_time']},
                       localize=localize),
         )
-        super().__init__(fields, *args, **kwargs)
+        super().__init__(fields, **kwargs)
 
     def compress(self, data_list):
         if data_list:
@@ -1146,10 +1138,10 @@ class SplitDateTimeField(MultiValueField):
 
 
 class GenericIPAddressField(CharField):
-    def __init__(self, protocol='both', unpack_ipv4=False, *args, **kwargs):
+    def __init__(self, *, protocol='both', unpack_ipv4=False, **kwargs):
         self.unpack_ipv4 = unpack_ipv4
         self.default_validators = validators.ip_address_validators(protocol, unpack_ipv4)[0]
-        super().__init__(*args, **kwargs)
+        super().__init__(**kwargs)
 
     def to_python(self, value):
         if value in self.empty_values:
@@ -1163,11 +1155,11 @@ class GenericIPAddressField(CharField):
 class SlugField(CharField):
     default_validators = [validators.validate_slug]
 
-    def __init__(self, *args, allow_unicode=False, **kwargs):
+    def __init__(self, *, allow_unicode=False, **kwargs):
         self.allow_unicode = allow_unicode
         if self.allow_unicode:
             self.default_validators = [validators.validate_unicode_slug]
-        super().__init__(*args, **kwargs)
+        super().__init__(**kwargs)
 
 
 class UUIDField(CharField):
diff --git a/django/forms/models.py b/django/forms/models.py
index 98b56392d0..3b5e1300e0 100644
--- a/django/forms/models.py
+++ b/django/forms/models.py
@@ -1128,10 +1128,10 @@ class ModelChoiceField(ChoiceField):
     }
     iterator = ModelChoiceIterator
 
-    def __init__(self, queryset, empty_label="---------",
+    def __init__(self, queryset, *, empty_label="---------",
                  required=True, widget=None, label=None, initial=None,
                  help_text='', to_field_name=None, limit_choices_to=None,
-                 *args, **kwargs):
+                 **kwargs):
         if required and (initial is not None):
             self.empty_label = None
         else:
@@ -1139,8 +1139,10 @@ class ModelChoiceField(ChoiceField):
 
         # Call Field instead of ChoiceField __init__() because we don't need
         # ChoiceField.__init__().
-        Field.__init__(self, required, widget, label, initial, help_text,
-                       *args, **kwargs)
+        Field.__init__(
+            self, required=required, widget=widget, label=label,
+            initial=initial, help_text=help_text, **kwargs
+        )
         self.queryset = queryset
         self.limit_choices_to = limit_choices_to   # limit the queryset later.
         self.to_field_name = to_field_name
@@ -1236,12 +1238,8 @@ class ModelMultipleChoiceField(ModelChoiceField):
         'invalid_pk_value': _('"%(pk)s" is not a valid value.')
     }
 
-    def __init__(self, queryset, required=True, widget=None, label=None,
-                 initial=None, help_text='', *args, **kwargs):
-        super().__init__(
-            queryset, None, required, widget, label, initial, help_text,
-            *args, **kwargs
-        )
+    def __init__(self, queryset, **kwargs):
+        super().__init__(queryset, empty_label=None, **kwargs)
 
     def to_python(self, value):
         if not value:
diff --git a/docs/ref/forms/fields.txt b/docs/ref/forms/fields.txt
index 442ec58da9..473ce3d4e0 100644
--- a/docs/ref/forms/fields.txt
+++ b/docs/ref/forms/fields.txt
@@ -1006,7 +1006,7 @@ Slightly complex built-in ``Field`` classes
             from django.core.validators import RegexValidator
 
             class PhoneField(MultiValueField):
-                def __init__(self, *args, **kwargs):
+                def __init__(self, **kwargs):
                     # Define one message for all fields.
                     error_messages = {
                         'incomplete': 'Enter a country calling code and a phone number.',
@@ -1030,7 +1030,7 @@ Slightly complex built-in ``Field`` classes
                     )
                     super().__init__(
                         error_messages=error_messages, fields=fields,
-                        require_all_fields=False, *args, **kwargs
+                        require_all_fields=False, **kwargs
                     )
 
     .. attribute:: MultiValueField.widget
diff --git a/docs/releases/2.0.txt b/docs/releases/2.0.txt
index d1ea0cef48..9c0f960d35 100644
--- a/docs/releases/2.0.txt
+++ b/docs/releases/2.0.txt
@@ -351,6 +351,19 @@ now prohibited, e.g.::
     ...
     TypeError: Cannot reverse a query once a slice has been taken.
 
+Form fields no longer accept optional arguments as positional arguments
+-----------------------------------------------------------------------
+
+To help prevent runtime errors due to incorrect ordering of form field
+arguments, optional arguments of built-in form fields are no longer accepted
+as positional arguments. For example::
+
+    forms.IntegerField(25, 10)
+
+raises an exception and should be replaced with::
+
+    forms.IntegerField(max_value=25, min_value=10)
+
 Miscellaneous
 -------------
 
diff --git a/tests/forms_tests/field_tests/test_charfield.py b/tests/forms_tests/field_tests/test_charfield.py
index a59291e33a..d51f9d8007 100644
--- a/tests/forms_tests/field_tests/test_charfield.py
+++ b/tests/forms_tests/field_tests/test_charfield.py
@@ -73,7 +73,8 @@ class CharFieldTest(FormFieldAssertionsMixin, SimpleTestCase):
             CharField(min_length='a')
         with self.assertRaises(ValueError):
             CharField(max_length='a')
-        with self.assertRaises(ValueError):
+        msg = '__init__() takes 1 positional argument but 2 were given'
+        with self.assertRaisesMessage(TypeError, msg):
             CharField('a')
 
     def test_charfield_widget_attrs(self):
diff --git a/tests/forms_tests/field_tests/test_multivaluefield.py b/tests/forms_tests/field_tests/test_multivaluefield.py
index a644e4a278..82d51ac657 100644
--- a/tests/forms_tests/field_tests/test_multivaluefield.py
+++ b/tests/forms_tests/field_tests/test_multivaluefield.py
@@ -31,13 +31,13 @@ class ComplexMultiWidget(MultiWidget):
 
 
 class ComplexField(MultiValueField):
-    def __init__(self, required=True, widget=None, label=None, initial=None):
+    def __init__(self, **kwargs):
         fields = (
             CharField(),
             MultipleChoiceField(choices=beatles),
             SplitDateTimeField(),
         )
-        super().__init__(fields, required, widget, label, initial)
+        super().__init__(fields, **kwargs)
 
     def compress(self, data_list):
         if data_list: