feat!: annotate types

WIP: annotate xblock/runtime.py
WIP: remove XBlock mixin from hierarchy, just use asserts, for backcompat?
WIP: DEPR non-string usage and definition keys?

BREAKING CHANGE: [Developers only]
Type-checked Python code using the XBlock API will likely need to be
updated in order to continue passing type-checking, since XBlock's
new annotations will trigger mypy (et al) to behave much more strictly.

NO BREAKING CHANGES for site operators, authors, learners, etc.

CHANGELOG.rst

@@ -5,13 +5,17 @@ Change history for XBlock
 Unreleased
 ----------
 
+6.0.0 - 2024-08-20
+------------------
+
+* added type hints to all public classes, methods, and functions
+
 5.1.0 - 2024-08-07
 ------------------
 
 * added ability to override an XBlock with the 'xblock.v1.overrides' entry point
 * added ability to override an XBlock Aside with the 'xblock_asides.v1.overrides' entry point
 
-
 5.0.0 - 2024-05-30
 ------------------
 

docs/conf.py

@@ -17,14 +17,6 @@
 
 import django
 
-MOCK_MODULES = [
-    'webob',
-    'lxml'
-]
-
-for mod_name in MOCK_MODULES:
-    sys.modules[mod_name] = mock.Mock(class_that_is_extended=object)
-
 
 # If extensions (or modules to document with autodoc) are in another directory,
 # add these directories to sys.path here. If the directory is relative to the
@@ -111,6 +103,11 @@
 # A list of ignored prefixes for module index sorting.
 #modindex_common_prefix = []
 
+# Display the type hints in the docs as part of the function signature.
+# This is the default, but it could be changed to "description" or "both".
+# https://www.sphinx-doc.org/en/master/usage/extensions/autodoc.html#confval-autodoc_typehints
+autodoc_typehints = "signature"
+
 # When auto-doc'ing a class, write the class' docstring and the __init__ docstring
 # into the class docs.
 autoclass_content = "both"
@@ -129,6 +126,40 @@
     ('py:class', 'aside_fn'),
     ('py:class', 'webob.Request'),
     ('py:class', 'webob.Response'),
+    ('py:class', 'webob.request.Request'),
+    ('py:class', 'webob.response.Response'),
+    ('py:class', 'lxml.etree._Element'),
+    # As of Sphinx==8.0.2 and Python 3.11, its seems that Sphinx has bug(s) that make it
+    # unable to consistently recognize classes in otherwise-valid type annotations. So, since
+    # adding type hints to XBlock, we've had to add this big list of warning suppressions.
+    # If you're reading this in the future with newer versions of Sphinx and/or Python, feel
+    # free to try to whittle down this list:
+    ('py:class', 'Blocklike'),
+    ('py:class', 'BlocklikeSubclass'),
+    ('py:class', 'DefinitionKey'),
+    ('py:class', 'FieldValue'),
+    ('py:class', 'InnerFieldValue'),
+    ('py:class', 'Request'),
+    ('py:class', 'Response'),
+    ('py:class', 'UniqueIdPlaceholder'),
+    ('py:class', 'Unset'),
+    ('py:class', 'UsageKey'),
+    ('py:class', 'etree._Element'),
+    ('py:class', 'importlib.metadata.EntryPoint'),
+    ('py:class', 'importlib.metadata.EntryPoint'),
+    ('py:class', 'opaque_keys.edx.keys.DefinitionKey'),
+    ('py:class', 'opaque_keys.edx.keys.LearningContextKey'),
+    ('py:class', 'opaque_keys.edx.keys.UsageKey'),
+    ('py:class', 't.Any'),
+    ('py:class', 't.Callable'),
+    ('py:class', 't.Iterable'),
+    ('py:class', 'web_fragments.fragment.Fragment'),
+    ('py:class', 'xblock.core.Blocklike'),
+    ('py:class', 'xblock.fields.FieldValue'),
+    ('py:class', 'xblock.fields.InnerFieldValue'),
+    ('py:class', 'xblock.fields.UniqueIdPlaceholder'),
+    ('py:class', 'xblock.fields.Unset'),
+    ('py:class', 'xblock.validation.Validation'),
 ]
 
 suppress_warnings = [

mypy.ini

@@ -4,6 +4,8 @@ ignore_missing_imports = False
 allow_untyped_globals = False
 files =
 	xblock
+exclude =
+	xblock.test
 
 # Ignore web_fragments typing until it has hints.
 [mypy-web_fragments.*]

xblock/__init__.py

@@ -2,4 +2,4 @@
 XBlock Courseware Components
 """
 
-__version__ = '5.1.0'
+__version__ = '6.0.0'

xblock/completable.py

@@ -1,6 +1,7 @@
 """
 This module defines CompletableXBlockMixin and completion mode enumeration.
 """
+from xblock.core import Blocklike, XBlockMixin
 
 
 class XBlockCompletionMode:
@@ -12,7 +13,7 @@ class XBlockCompletionMode:
     EXCLUDED = "excluded"
 
     @classmethod
-    def get_mode(cls, block_class):
+    def get_mode(cls, block_class: Blocklike | type[Blocklike]) -> str:
         """
         Return the effective completion mode for a given block.
 
@@ -21,17 +22,17 @@ def get_mode(cls, block_class):
         return getattr(block_class, 'completion_mode', cls.COMPLETABLE)
 
 
-class CompletableXBlockMixin:
+class CompletableXBlockMixin(XBlockMixin):
     """
     This mixin sets attributes and provides helper method to integrate XBlock with Completion API.
     """
 
-    has_custom_completion = True
-    completion_mode = XBlockCompletionMode.COMPLETABLE
+    has_custom_completion: bool = True
+    completion_mode: str = XBlockCompletionMode.COMPLETABLE
 
     # To read more on the debate about using the terms percent vs ratio, see:
     # https://openedx.atlassian.net/wiki/spaces/OpenDev/pages/245465398/Naming+with+Percent+or+Ratio
-    def emit_completion(self, completion_percent):
+    def emit_completion(self, completion_percent: float) -> None:
         """
         Emits completion event through Completion API.