Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Avoid missing base item fields in item loaders #3047

Closed
wants to merge 1 commit into from
Closed

Avoid missing base item fields in item loaders #3047

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Jump to
Jump to file
Failed to load files.
Diff view
Diff view
2 changes: 1 addition & 1 deletion scrapy/loader/__init__.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -113,7 +113,7 @@ def load_item(self):
item = self.item
for field_name in tuple(self._values):
value = self.get_output_value(field_name)
if value is not None:
if value is not None and value != []:
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I can imagine cases where someone expects a failed load to still populate an empty list, and this change might break things for them. Perhaps instead the code should check whether adding an empty list would clobber an existing field? Because, per your issue in #3046 I think that's the more bug-like behaviour?

item[field_name] = value

return item
Expand Down
9 changes: 9 additions & 0 deletions tests/test_loader.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -99,6 +99,15 @@ class MyLoader(ItemLoader):
il.replace_value('sku', [valid_fragment], re=sku_re)
self.assertEqual(il.load_item()['sku'], u'1234')

def test_get_output_value_before_load_item(self):
item = TestItem(url='http://example.com', summary='foo bar')
il = ItemLoader(item)
il.get_output_value('url')
self.assertEqual(il.load_item(), {
'url': 'http://example.com',
'summary': 'foo bar',
})

def test_self_referencing_loader(self):
class MyLoader(ItemLoader):
url_out = TakeFirst()
Expand Down