Fix dsfr_input_class_attr triggering eaunexpected validation in DsfrB…

…aseForm.__init__ (#190)

dsfr/test/test_forms.py

@@ -0,0 +1,54 @@
+from typing import NoReturn
+
+from django import forms
+from django.test import SimpleTestCase
+
+
+from dsfr.forms import DsfrBaseForm
+
+
+class DsfrBaseFormTestCase(SimpleTestCase):
+    class TestForm(DsfrBaseForm):
+        book_format = forms.ChoiceField(
+            label="Format",
+            choices=(
+                ("PAPER", "Papier"),
+                ("NUM", "Numérique"),
+            ),
+        )
+        book_format2 = forms.ChoiceField(
+            label="Format",
+            choices=(
+                ("PAPER", "Papier"),
+                ("NUM", "Numérique"),
+            ),
+            widget=forms.RadioSelect,
+        )
+        user_id = forms.CharField(widget=forms.HiddenInput)
+
+    def test_init_sets_attributes(self):
+        form = self.TestForm(data={})
+        self.assertEqual(form.fields["book_format"].widget.attrs["class"], "fr-select")
+        self.assertEqual(
+            form.fields["book_format"].widget.group_class, "fr-select-group"
+        )
+        self.assertEqual(form.fields["book_format2"].widget.attrs["dsfr"], "dsfr")
+        self.assertEqual(
+            form.fields["book_format2"].widget.group_class, "fr-radio-group"
+        )
+        self.assertEqual(form.fields["user_id"].widget.attrs, {})
+
+    def test_init_dont_trigger_form_validation(self):
+        test_ctx = self
+
+        class AssertForm(self.TestForm):
+            @property
+            def errors(self) -> NoReturn:
+                test_ctx.fail("No validation expected")
+
+        # __init__ should not trigger validation
+        AssertForm(data={})
+
+        with self.assertRaises(self.failureException):
+            # is_valid should trigger validation
+            AssertForm(data={}).is_valid()

dsfr/utils.py

@@ -133,7 +133,8 @@ def dsfr_input_class_attr(bf: BoundField):
         ):
             bf.field.widget.attrs["class"] = "fr-input"
 
-    if bf.errors:
+    # bf.errors triggers form validation. We need to check form._errors to prevent that
+    if bf.form._errors and bf.errors:
         bf.field.widget.attrs.update(
             {"aria-invalid": "true", "aria-describedby": f"{bf.auto_id}-desc-error"}
         )