fix: Course blocks API with param return_type=list

[qasimgulzar]

Discussion: edx (New).
Issue Link
Endpoint: {LMS_HOST}/api/courses/v1/blocks/?course_id={COURSE_ID}&return_type=list

Root cause
When return_type is set to list in querystring the api endpoint is crashing because it is calling dict method on ReturnList type instance to get blocks.

Solution
I have added a type check before fetching blocks if it is getting ReturnList I am treating it as list. otherwise following the old path.

Stacktrace

File "/opened/venv/lib/python3.8/site-packages/django/core/handlers/exception.py", line 55, in inner
response = get_response (request)
File "/openedx/venv/lib/python3.8/site-packages/django/core/handlers/base.py",line 197, in _get_response
response = wrapped_callback(request,
*callback_args,
**callback_kwargs)
File "/opened/venv/lib/python3.8/site-packages/django/views/decorators/csrf.py",line 56, in wrapper_view return view_func(*args,
**kwargs)
File "/opened/venv/lib/python3.8/site-packages/django/views/generic/base.py",line 104, in view return self.dispatch(request, *args,
**kwargs)
File "/opened/venv/lib/python3.8/site-packages/django/utils/decorators.py",line46,in_wrapper return bound_method(*args
**kwargs)
File "/opened×/venv/lib/python3.8/site-packages/rest_framework/views.py", line 509, in dispatch
response = self. handle_exception (exc)
File "/opened/venv/lib/python3.8/site-packages/rest_framework/views.py",line 506, in dispatch
response = handler(request, *args, **kwargs)
File "/opened/venv/lib/python3.8/site-packages/rest_framework/generics.py", line 199, in get return self.list(request, *args, **kwargs)
File "/opened×/edx-platform/./lms/djangoapps/course_api/blocks/views.py", line 315, in list
response = filter_discussion_blocks_from_response(response,
course_key)
File "/opened/edx-platform/./lms/djangoapps/course_api/blocks/utils.py",line19,infilter_discussion_xblocks_from_response key for key, value in response.data.get('blocks' {}).items()
AttributeError:
'ReturnList' object has no attribute
'get'

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[regisb]

This PR is now ready for review. Cc @vunguyen-dmt who reported the initial issue #34379

[qasimgulzar]

@openedx/2u-aperture could you please help reviewing this PR?

[justinhynes]

Hi @qasimgulzar,

This particular bit of code lies outside of Aperture's ownership/maintenance load, nor does the team have any experience or knowledge of the functionality in the course_api app. I'm afraid we're probably not the best team positioned to help here.

I believe you might be looking for folks from the Aurora team at 2U, who look to be maintainers of this functionality (sorry for any confusion!)

[qasimgulzar]

@justinhynes thank you very much for you response, let me try to find someone relevant to this PR.
I apologise to bother you :)

[feanil]

Generally looks good to me other than this, @qasimgulzar do you want to put the imports back as they were? I think the rest of this looks good to land.

[feanil]

This seems like a weird formatting change, why remove the parens on the first entry and add them to the last one?

[qasimgulzar]

@feanil I had run iSort on this file but yes it seems weird with / I have manually updated the line and added parentheses. Other than this there were few unused imports do you want me to put those back as well?

[feanil]

I think dropping the unused imports is great. This is fine to leave in as-is if this is just weird isort behavior.

[openedx-webhooks]

@qasimgulzar 🎉 Your pull request was merged! Please take a moment to answer a two question survey so we can improve your experience in the future.

[edx-pipeline-bot]

2U Release Notice: This PR has been deployed to the edX staging environment in preparation for a release to production.

[edx-pipeline-bot]

2U Release Notice: This PR has been deployed to the edX production environment.