Support declarations in FileField/ImageField.

Previously, the declarations (``factory.Sequence`` & co)  weren't properly computed.

docs/changelog.rst

@@ -10,6 +10,8 @@ ChangeLog
 *Bugfix:*
 
     - Respect custom managers in :class:`~factory.django.DjangoModelFactory` (see :issue:`192`)
+    - Allow passing declarations (e.g :class:`~factory.Sequence`) as parameters to :class:`~factory.django.FileField`
+      and :class:`~factory.django.ImageField`.
 
 .. _v2.5.0:
 

factory/django.py

@@ -147,6 +147,7 @@ class FileField(declarations.ParameteredAttribute):
     """Helper to fill in django.db.models.FileField from a Factory."""
 
     DEFAULT_FILENAME = 'example.dat'
+    EXTEND_CONTAINERS = True
 
     def __init__(self, **defaults):
         require_django()
@@ -156,10 +157,8 @@ def _make_data(self, params):
         """Create data for the field."""
         return params.get('data', b'')
 
-    def _make_content(self, extra):
+    def _make_content(self, params):
         path = ''
-        params = dict(self.defaults)
-        params.update(extra)
 
         if params.get('from_path') and params.get('from_file'):
             raise ValueError(
@@ -189,10 +188,12 @@ def _make_content(self, extra):
         filename = params.get('filename', default_filename)
         return filename, content
 
-    def evaluate(self, sequence, obj, create, extra=None, containers=()):
+    def generate(self, sequence, obj, create, params):
         """Fill in the field."""
 
-        filename, content = self._make_content(extra)
+        params.setdefault('__sequence', sequence)
+        params = base.DictFactory.simple_generate(create, **params)
+        filename, content = self._make_content(params)
         return django_files.File(content.file, filename)
 
 

tests/djapp/models.py

@@ -79,6 +79,7 @@ class WithFile(models.Model):
 
     class WithImage(models.Model):
         animage = models.ImageField(upload_to=WITHFILE_UPLOAD_TO)
+        size = models.IntegerField(default=0)
 
 else:
     class WithImage(models.Model):

tests/test_django.py

@@ -497,6 +497,17 @@ def test_default_create(self):
         self.assertEqual(100, o.animage.height)
         self.assertEqual('django/example.jpg', o.animage.name)
 
+    def test_complex_create(self):
+        o = WithImageFactory.create(
+            size=10,
+            animage__filename=factory.Sequence(lambda n: 'img%d.jpg' % n),
+            __sequence=42,
+            animage__width=factory.SelfAttribute('..size'),
+            animage__height=factory.SelfAttribute('width'),
+        )
+        self.assertIsNotNone(o.pk)
+        self.assertEqual('django/img42.jpg', o.animage.name)
+
     def test_with_content(self):
         o = WithImageFactory.build(animage__width=13, animage__color='red')
         self.assertIsNone(o.pk)