WIP: Separate file field in django form constructor

AUTHORS.rst

@@ -23,6 +23,7 @@ their individual contributions.
 * `Andrea Reina <https://www.github.com/andreareina>`_
 * `Andrew Sansom <https://www.github.com/qthequartermasterman>`_
 * `Anne Archibald <https://www.github.com/td-anne>`_
+* `Arjoonn Sharma <https://github.com/thesage21>`_
 * `Ben Anhalt <https://github.com/benanhalt>`_
 * `Ben Peterson <https://github.com/killthrush>`_ ([email protected])
 * `Benjamin Lee <https://github.com/Benjamin-Lee>`_ ([email protected])

hypothesis-python/RELEASE.rst

@@ -0,0 +1,6 @@
+RELEASE_TYPE: minor
+
+This release fixes file field handling for django forms when using
+:func:`~hypothesis.extra.django.from_form` (:issue:`4093`).
+
+Thanks to Arjoonn Sharma for this fix!

hypothesis-python/src/hypothesis/extra/django/_impl.py

@@ -179,7 +179,10 @@ def from_form(
 
     unbound_form = form(**form_kwargs)
     fields_by_name = {}
+    file_fields_by_name = set()
     for name, field in unbound_form.fields.items():
+        if isinstance(field, df.FileField):
+            file_fields_by_name.add(name)
         if isinstance(field, df.MultiValueField):
             # PS: So this is a little strange, but MultiValueFields must
             # have their form data encoded in a particular way for the
@@ -201,11 +204,20 @@ def from_form(
     for name, field in sorted(fields_by_name.items()):
         if name not in field_strategies and not field.disabled:
             field_strategies[name] = from_field(field)
+    # File strategies need to be passed separately into the form constructor
+    # and so we create a separate dict for them. These fields are not supposed
+    # to be sent via the data constructor
+    # ref: https://docs.djangoproject.com/en/5.1/topics/http/file-uploads/#id4
+    file_strategies = {}
+    for name in list(field_strategies):
+        if name in file_fields_by_name:
+            file_strategies[name] = field_strategies.pop(name)
 
     return _forms_impl(
         st.builds(
             partial(form, **form_kwargs),  # type: ignore
             data=st.fixed_dictionaries(field_strategies),  # type: ignore
+            files=st.fixed_dictionaries(file_strategies),  # type: ignore
         )
     )
 

hypothesis-python/tests/django/toystore/forms.py

@@ -22,6 +22,7 @@
     Company,
     CouldBeCharming,
     Customer,
+    FileFields,
     ManyNumerics,
     ManyTimes,
     OddFields,
@@ -46,6 +47,12 @@ class Meta:
         fields = "__all__"
 
 
+class FileFieldsForm(ReprModelForm):
+    class Meta:
+        model = FileFields
+        fields = "__all__"
+
+
 class CustomerForm(ReprModelForm):
     class Meta:
         model = Customer

hypothesis-python/tests/django/toystore/models.py

@@ -99,6 +99,10 @@ class CustomishDefault(models.Model):
     customish = CustomishField(default="b")
 
 
+class FileFields(models.Model):
+    file1 = models.FileField()
+
+
 class MandatoryComputed(models.Model):
     name = models.CharField(max_length=100, unique=True)
     company = models.ForeignKey(Company, null=False, on_delete=models.CASCADE)

hypothesis-python/tests/django/toystore/test_given_forms.py

@@ -26,6 +26,7 @@
     CustomerForm,
     DynamicForm,
     EmailFieldForm,
+    FileFieldsForm,
     InternetProtocolForm,
     ManyMultiValueForm,
     ManyNumericsForm,
@@ -130,6 +131,12 @@ def test_tight_validators_form(self, x):
         self.assertTrue(1 <= x.data["_float_one_to_five"] <= 5)
         self.assertTrue(5 <= len(x.data["_string_five_to_ten"]) <= 10)
 
+    @given(from_form(FileFieldsForm))
+    def test_file_fields_form(self, x):
+        assert x.is_valid()
+        if "file1" in x.data:
+            self.assertTrue(x.data["file1"])
+
     @given(from_form(UsernameForm))
     def test_username_form(self, username_form):
         self.assertTrue(username_form.is_valid())