Fix ModelForm issue in django 3.0+, which caused fields with required…

…=False validation by model fields (#19)

1. Fix ModelForm issue in django 3.0+, which caused fields with required=False validation by model fields
2. Replaced django 2.1 with django 4.0 in test matrix

.github/workflows/python-tests.yml

@@ -12,7 +12,13 @@ jobs:
     strategy:
       matrix:
         python-version: ["3.6", "3.7", "3.8", "3.9", "3.10"]
-        django-version: ["2.1", "2.2", "3.0", "3.1", "3.2"]
+        django-version: ["2.2", "3.0", "3.1", "3.2", "4.0"]
+        exclude:
+          # Django 4.0+ doesn't support python 3.6, 3.7
+          - python-version: "3.6"
+            django-version: "4.0"
+          - python-version: "3.7"
+            django-version: "4.0"
 
     steps:
     - uses: actions/checkout@v2

Dockerfile

@@ -33,8 +33,7 @@ WORKDIR /app/src
 # Install dependencies
 # set -eu "breaks" pipeline on first error
 COPY ./requirements-test.txt /app/requirements-test.txt
-RUN --mount=type=cache,target=/root/.cache/pip \
-  set -eu && \
+RUN set -eu && \
   python3 -m pip install --upgrade pip setuptools wheel  && \
   python3 -m pip install --upgrade --requirement /app/requirements-test.txt
 

README.md

@@ -6,7 +6,7 @@ Extended form fields to validate REST-request data via django.forms.
 ## Requirements
 * Python 3.6+  
   Other versions may also work but not tested automatically
-* Django 2.1+  
+* Django 2.2+  
   Other versions may also work but not tested automatically
 * jsonschema
 * pytz

setup.cfg

@@ -1,5 +1,5 @@
 [metadata]
-description-file = README.md
+description_file = README.md
 
 [bdist_wheel]
 universal = 1

setup.py

@@ -13,7 +13,7 @@
 
 setup(
     name='django-rest-form-fields',
-    version='1.3.3',
+    version='1.3.4',
     packages=['django_rest_form_fields'],
     package_dir={'': 'src'},
     url='https://github.com/M1hacka/django-rest-form-fields',

src/django_rest_form_fields/fields.py

@@ -52,7 +52,7 @@ class EmptyStringFixMixing(BaseField):
     # 2) RestCharField and child classes don't allow to pass empty string if required=True
     # 3) run_validators() method is not called if value is in empty_values, so min_length validation doesn't work
     #    for RestCharField and value=''
-    empty_values = []
+    empty_values = [None]
 
     def to_python(self, value):  # type: (Any) -> Optional[str]
         return None if value is None else super(EmptyStringFixMixing, self).to_python(value)

tests/test_forms.py

@@ -81,3 +81,40 @@ def test_initial(self):
                         {'dest': 'init', 'model_field': 'm'})
         self._test_form(BaseModelForm, {'dest': RestCharField(source='src', required=False, initial='init')},
                         {'dest': 'test', 'model_field': 'm'})
+
+
+class RequiredBaseModelFormTest(TestCase):
+    def test_base_form(self):
+        class TestForm(BaseForm):
+            test = RestCharField(max_length=255, required=False)
+
+        f = TestForm({})
+        f.full_clean()
+        self.assertTrue(f.is_valid())
+        self.assertDictEqual({'test': None}, f.cleaned_data)
+
+    def test_model_form(self):
+        class TestForm(BaseModelForm):
+            class Meta:
+                model = ModelExample
+                fields = ('model_field',)
+
+            model_field = RestCharField(max_length=255, required=False)
+
+        f = TestForm({})
+        f.full_clean()
+        self.assertTrue(f.is_valid())
+        self.assertDictEqual({'model_field': None}, f.cleaned_data)
+
+    def test_model_form_initial(self):
+        class TestForm(BaseModelForm):
+            class Meta:
+                model = ModelExample
+                fields = ('model_field',)
+
+            model_field = RestCharField(max_length=255, required=False, initial='init')
+
+        f = TestForm({})
+        f.full_clean()
+        self.assertTrue(f.is_valid())
+        self.assertDictEqual({'model_field': 'init'}, f.cleaned_data)