Fixed #35870 -- Made blank choice label in forms more accessible.

Added new constant django.db.models.fields.BLANK_CHOICE_LABEL for
an accessible and translatable blank choice label in forms.
Deprecated django.db.models.fields.BLANK_CHOICE_DASH constant.
Added the immediately deprecated transitional setting
USE_BLANK_CHOICE_DASH.

Co-Authored-By: Marijke Luttekes <mail@marijkeluttekes.dev>

7 files changed, 106 insertions, 9 deletions

diff --git a/tests/forms_tests/field_tests/test_typedchoicefield.py b/tests/forms_tests/field_tests/test_typedchoicefield.py
index 3537623272..fe5cbe12ee 100644
--- a/tests/forms_tests/field_tests/test_typedchoicefield.py
+++ b/tests/forms_tests/field_tests/test_typedchoicefield.py
@@ -1,6 +1,7 @@
 import decimal
 
 from django.core.exceptions import ValidationError
+from django.db.models.utils import get_blank_choice_label
 from django.forms import TypedChoiceField
 from django.test import SimpleTestCase
 
@@ -62,7 +63,11 @@ class TypedChoiceFieldTest(SimpleTestCase):
         self.assertFalse(f.has_changed("1", "1"))
 
         f = TypedChoiceField(
-            choices=[("", "---------"), ("a", "a"), ("b", "b")],
+            choices=[
+                ("", get_blank_choice_label()),
+                ("a", "a"),
+                ("b", "b"),
+            ],
             coerce=str,
             required=False,
             initial=None,
diff --git a/tests/forms_tests/locale/de/LC_MESSAGES/django.mo b/tests/forms_tests/locale/de/LC_MESSAGES/django.mo
new file mode 100644
index 0000000000..f2695ea426
--- /dev/null
+++ b/tests/forms_tests/locale/de/LC_MESSAGES/django.mo
diff --git a/tests/forms_tests/locale/de/LC_MESSAGES/django.po b/tests/forms_tests/locale/de/LC_MESSAGES/django.po
new file mode 100644
index 0000000000..e118e28d98
--- /dev/null
+++ b/tests/forms_tests/locale/de/LC_MESSAGES/django.po
@@ -0,0 +1,14 @@
+# This file is distributed under the same license as the Django package.
+#
+msgid ""
+msgstr ""
+"Project-Id-Version: django\n"
+"Report-Msgid-Bugs-To: \n"
+"MIME-Version: 1.0\n"
+"Content-Type: text/plain; charset=UTF-8\n"
+"Content-Transfer-Encoding: 8bit\n"
+"Language: de\n"
+"Plural-Forms: nplurals=2; plural=(n != 1);\n"
+
+msgid "- Select an option -"
+msgstr "- Wähle eine Option -"
diff --git a/tests/forms_tests/locale/de/__init__.py b/tests/forms_tests/locale/de/__init__.py
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/tests/forms_tests/locale/de/__init__.py
diff --git a/tests/forms_tests/tests/test_forms.py b/tests/forms_tests/tests/test_forms.py
index 14fbc19a59..2c1ec78650 100644
--- a/tests/forms_tests/tests/test_forms.py
+++ b/tests/forms_tests/tests/test_forms.py
@@ -1,11 +1,14 @@
 import copy
 import datetime
 import json
+import textwrap
 import uuid
 
+from django.conf import USE_BLANK_CHOICE_DASH_DEPRECATED_MSG
 from django.core.exceptions import NON_FIELD_ERRORS
 from django.core.files.uploadedfile import SimpleUploadedFile
 from django.core.validators import MaxValueValidator, RegexValidator
+from django.db.models.utils import get_blank_choice_label
 from django.forms import (
     BooleanField,
     BoundField,
@@ -42,9 +45,10 @@ from django.forms.renderers import DjangoTemplates, get_default_renderer
 from django.forms.utils import ErrorDict, ErrorList
 from django.http import QueryDict
 from django.template import Context, Template
-from django.test import SimpleTestCase
+from django.test import SimpleTestCase, ignore_warnings
 from django.test.utils import override_settings
 from django.utils.datastructures import MultiValueDict
+from django.utils.deprecation import RemovedInDjango70Warning
 from django.utils.safestring import mark_safe
 
 from . import jinja2_tests
@@ -797,6 +801,37 @@ aria-describedby="id_birthday_error">
 </select>""",
         )
 
+    # RemovedInDjango70Warning
+    @ignore_warnings(category=RemovedInDjango70Warning)
+    @override_settings(USE_BLANK_CHOICE_DASH=True)
+    def test_blank_choice_dash(self):
+        class SomeForm(Form):
+            somechoices = ChoiceField(
+                choices=(
+                    ("0", get_blank_choice_label()),
+                    ("1", "Test 1"),
+                    ("2", "Test 2"),
+                )
+            )
+
+        f = SomeForm()
+
+        self.assertHTMLEqual(
+            f.as_p(),
+            textwrap.dedent("""
+            <p>
+                <label for="id_somechoices">Somechoices:</label>
+                <select name="somechoices" id="id_somechoices">
+                <option value="0">---------</option>
+                <option value="1">Test 1</option>
+                <option value="2">Test 2</option></select>
+            </p>"""),
+        )
+
+        self.assertWarnsMessage(
+            RemovedInDjango70Warning, USE_BLANK_CHOICE_DASH_DEPRECATED_MSG
+        )
+
     def test_forms_with_radio(self):
         # Add widget=RadioSelect to use that widget with a ChoiceField.
         f = FrameworkForm(auto_id=False)
diff --git a/tests/forms_tests/tests/test_i18n.py b/tests/forms_tests/tests/test_i18n.py
index 5b8d92c0f6..fe6a67dd16 100644
--- a/tests/forms_tests/tests/test_i18n.py
+++ b/tests/forms_tests/tests/test_i18n.py
@@ -1,3 +1,6 @@
+import textwrap
+
+from django.db.models.utils import get_blank_choice_label
 from django.forms import (
     CharField,
     ChoiceField,
@@ -122,6 +125,41 @@ class FormsI18nTests(SimpleTestCase):
 
         CopyForm()
 
+    def test_blank_choice_label(self):
+        class SomeForm(Form):
+            somechoices = ChoiceField(
+                choices=(
+                    ("0", get_blank_choice_label()),
+                    ("1", "Test 1"),
+                    ("2", "Test 2"),
+                )
+            )
+
+        f = SomeForm()
+
+        self.assertHTMLEqual(
+            f.as_p(),
+            textwrap.dedent("""
+            <p>
+                <label for="id_somechoices">Somechoices:</label>
+                <select name="somechoices" id="id_somechoices">
+                <option value="0">- Select an option -</option>
+                <option value="1">Test 1</option>
+                <option value="2">Test 2</option></select>
+            </p>"""),
+        )
+
+        with translation.override("de"):
+            self.assertHTMLEqual(
+                f.as_p(),
+                textwrap.dedent("""<p><label for="id_somechoices">Somechoices:</label>
+                    <select name="somechoices" id="id_somechoices">
+                    <option value="0">- Wähle eine Option -</option>
+                    <option value="1">Test 1</option>
+                    <option value="2">Test 2</option></select>
+                </p>"""),
+            )
+
 
 @jinja2_tests
 class Jinja2FormsI18nTests(FormsI18nTests):
diff --git a/tests/forms_tests/widget_tests/test_radioselect.py b/tests/forms_tests/widget_tests/test_radioselect.py
index be336151ef..a4d4919009 100644
--- a/tests/forms_tests/widget_tests/test_radioselect.py
+++ b/tests/forms_tests/widget_tests/test_radioselect.py
@@ -1,12 +1,13 @@
 import datetime
 
+from django.db.models.utils import get_blank_choice_label
 from django.forms import ChoiceField, Form, MultiWidget, RadioSelect, TextInput
 from django.test import override_settings
 from django.utils.safestring import mark_safe
 
 from .test_choicewidget import ChoiceWidgetTest
 
-BLANK_CHOICE_DASH = (("", "------"),)
+BLANK_CHOICE = (("", get_blank_choice_label()),)
 
 
 class RadioSelectTest(ChoiceWidgetTest):
@@ -16,7 +17,9 @@ class RadioSelectTest(ChoiceWidgetTest):
         html = """
         <div>
           <div>
-            <label><input type="radio" name="beatle" value="">------</label>
+            <label><input type="radio" name="beatle" value="">
+              - Select an option -
+            </label>
           </div>
           <div>
             <label><input checked type="radio" name="beatle" value="J">John</label>
@@ -32,7 +35,7 @@ class RadioSelectTest(ChoiceWidgetTest):
           </div>
         </div>
         """
-        beatles_with_blank = BLANK_CHOICE_DASH + self.beatles
+        beatles_with_blank = BLANK_CHOICE + self.beatles
         for choices in (beatles_with_blank, dict(beatles_with_blank)):
             with self.subTest(choices):
                 self.check_html(self.widget(choices=choices), "beatle", "J", html=html)
@@ -83,11 +86,13 @@ class RadioSelectTest(ChoiceWidgetTest):
         """
         If value is None, none of the options are selected.
         """
-        choices = BLANK_CHOICE_DASH + self.beatles
+        choices = BLANK_CHOICE + self.beatles
         html = """
         <div>
           <div>
-            <label><input checked type="radio" name="beatle" value="">------</label>
+            <label><input checked type="radio" name="beatle" value="">
+              - Select an option -
+            </label>
           </div>
           <div>
             <label><input type="radio" name="beatle" value="J">John</label>
@@ -463,11 +468,11 @@ class RadioSelectTest(ChoiceWidgetTest):
 
     def test_render_as_subwidget(self):
         """A RadioSelect as a subwidget of MultiWidget."""
-        choices = BLANK_CHOICE_DASH + self.beatles
+        choices = BLANK_CHOICE + self.beatles
         html = """
         <div>
           <div><label>
-            <input type="radio" name="beatle_0" value="">------</label>
+            <input type="radio" name="beatle_0" value="">- Select an option -</label>
           </div>
           <div><label>
             <input checked type="radio" name="beatle_0" value="J">John</label>