After we merged this PR: https://github.com/openedx/edx-platform/pull/33920
this error began popping up in logs:
Unable to load XBlock 'staffgradedxblock'
....
ImportError: cannot import name 'get_course_blocks' from
partially initialized module 'lms.djangoapps.course_blocks.api'
(most likely due to a circular import) ...
The root cause was the new imports of `derived_key` and `BlockKey` into
xmodule/library_content_block.py. Those new imports come from
xmodule/modulestore/store_utilities.py, which runs
`XBlock.load_classes()` at the module level, which fails because we are
still in the process of loading xmodule/library_content_block.
As a solution, we move both `derived_key` and `BlockKey` to
xmodule/util/keys.py. We could potentially move that file to opaque-keys
eventually, depending on how well we think that those concepts generalize.
Also:
* We rename the function from derived_key to derive_key, as
functions should be verbs.
* We combine the first to parameters of derive_key (a source ContextKey
and a source BlockKey) into a single parameter (a source UsageKey). In
my opinion, this makes the function call easier to understand.
* chore: typing + fixes for content_staging
* chore: typing + fixes for learning_sequences
* chore: typing + fixes for content_libraries
* chore: typing + fixes for new XBlock runtime
* feat: type hinting more code with mypy
The edx-platform codebase already includes quite a few type annotations, but
they were not regularly checked. This may cause problems, when the annotations
themselves include errors (as we found out in some of the learning_sequences
annotations). So here, we add mypy as a dev requirement and introduce a make
command to run mypy regularly. Mypy runs on a very small portion of the total
edx-platform, as configured in mypy.ini. Our hope is that developers will add
more and more modules to this configuration file, until we can eventually run
mypy on the full code base.
See discussion: https://discuss.openedx.org/t/dev-notes-running-mypy-on-edx-platform/4860
