Build out large Act blocks option (jamescooke#218)

* Add LARGE act block style option value

* Restore add_node_parents() helper

* Reinstate greedy act blocks for Large act block style

* Reinstate test on add_node_parents

* Add pytest icdiff to test requirements

* Add test on Function.mark_act()

* Fix typo in tox config

* Prevent mypy caches leaking between runs on local

* Fix lint: ignore stuffing of parent attr; update comment

* Bump Black to 23.3.0 from 22.12.0

* Adjust Checker to use a default config class attr

* Remove old file

* Build out FirstChildFinder to help with large style act blocks

* Fix lint: remove unused import

* Switch from adding parents to using first child finder visitor

* Stub in temp tox config to run large act block config

* Update Black formatted examples and add environment to tox

* Update CHANGELOG

CHANGELOG.rst

@@ -23,17 +23,22 @@ Unreleased_
 See also `latest documentation
 <https://flake8-aaa.readthedocs.io/en/latest/#__unreleased_marker__>`_.
 
-* ⛏️ Move Black formatted test examples to their own directory. This will help
+* 🎈 New "large" Act block style option added. This allows context managers to
+  join the Act block when they directly wrap the Act node. This behaviour is
+  provided to provide compatibility with Black versions ``23.*``. Fixes `issue
+  200 <https://github.com/jamescooke/flake8-aaa/issues/200>`_.
+
+* ⛏️ Moved Black formatted test examples to their own directory. This helps
   when running Flake8 against Black formatted tests which need
   ``--aaa-act-block-style=large``. Also fix up associated Makefile recipes and
   update example README file.
 
-* ⛏️ Remove list of nodes from ``Block`` class and instead keep the start and
+* ⛏️ Removed list of nodes from ``Block`` class and instead kept the start and
   end line numbers of the block. This allows for any structural discoveries
   while doing AST node traversal (e.g. when parsing Large style Act blocks) to
   be used to calculate the size of the Act block itself. The alternative would
-  be to store the list of nodes in the Act block, and then re-walk them when
-  working out the block's span, which would be duplication of effort.
+  have been to store the list of nodes in the Act block, and then re-walk them
+  when working out the block's span, which would be duplication of effort.
 
 * ⛏️ Remove unused ``MultiNodeBlock``.
 

Makefile

@@ -30,7 +30,7 @@ lintexamples:
 	flake8 examples/good examples/bad | sort > flake8.out
 	diff examples/bad/flake8_expected.out flake8.out
 	@echo "=== mypy ==="
-	mypy examples/conftest.py examples/good --ignore-missing-imports --exclude examples/good/black/
+	mypy examples/conftest.py examples/good --ignore-missing-imports --exclude examples/black/ --no-incremental
 	mypy examples/bad --ignore-missing-imports
 	@echo "=== black ==="
 	black --check --diff --verbose examples/black

configs/black_compatible.ini

@@ -0,0 +1,2 @@
+[flake8]
+aaa_act_block_style = large

docs/command_line.rst

@@ -6,6 +6,12 @@ debugging. Its goal is to show the state of analysed test functions, which
 lines are considered to be parts of which blocks and any errors that have been
 found.
 
+.. warning::
+
+    Command line mode does not support ``--aaa-act-block-style=large`` option
+    or associated configuration. `Issue regarding this is open on GitHub
+    <https://github.com/jamescooke/flake8-aaa/issues/217>`_.
+
 Invocation, output and return value
 -----------------------------------
 

examples/black/test_django_fakery_factories.py

@@ -22,7 +22,6 @@ def test_default(self):
 
 
 class TestUserFactory(TestCase):
-
     user_model = get_user_model()
 
     def test_default(self):

examples/black/test_with_statement.py

@@ -1,4 +1,5 @@
 import io
+import pathlib
 import warnings
 from typing import Generator, List
 
@@ -12,44 +13,61 @@ def test_pytest_raises() -> None:
         list()[0]
 
 
-def test_deprecation_warning():
+def test_deprecation_warning() -> None:
     with pytest.deprecated_call():
         warnings.warn("deprecate warning", DeprecationWarning)
 
 
-def test_user_warning():
+def test_user_warning() -> None:
     with pytest.warns(UserWarning):
         warnings.warn("my warning", UserWarning)
 
 
 # --- Use of context managers in tests ---
 
 
-def test_simple(hello_world_path) -> None:
+def test_simple(hello_world_path: pathlib.Path) -> None:
     """
-    `with` statement is part of arrange. Blank lines are maintained around Act.
+    Test checks "simple" context manager in both Act block styles:
+
+    * DEFAULT: `with` statement is part of arrange. Blank lines are maintained
+        around Act.
+    * LARGE: When formatted with Black, context manager is squashed against act
+        node. Large act block mode allows the context manager to join the act
+        block and linting passes.
     """
     with open(hello_world_path) as f:
-
         result = f.read()
 
     assert result == "Hello World!\n"
 
 
-def test_whole(hello_world_path) -> None:
+def test_whole(hello_world_path: pathlib.Path) -> None:
     """
-    `with` statement wraps whole of test
+    `with` statement wraps whole of test. This checks context manager in both
+    Act block styles:
+
+    * DEFAULT: `with` statement is part of Arrange. Result assignment is Act.
+        Blank lines are maintained.
+    * LARGE: When formatted with Black, context manager is squashed against
+        result assignment. Act block grows to consume context manager because
+        it's the first node in the context manager body. However, new large Act
+        block _still_ finishes at the end of the result assignment. There is
+        then a blank line and the assert block, even though that's inside the
+        context manager.
     """
     with open(hello_world_path) as f:
-
         result = f.read()
 
         assert result == "Hello World!\n"
+        assert f.fileno() > 0
 
 
-def test_extra_arrange(hello_world_path) -> None:
+def test_extra_arrange(hello_world_path: pathlib.Path) -> None:
     """
-    Any extra arrangement goes in the `with` block.
+    Any extra arrangement goes in the `with` block. Works "as-is" for Large act
+    block style because `f.read()` node prevents the `result = ` act node from
+    joining the `with` context manager.
     """
     with open(hello_world_path) as f:
         f.read()
@@ -59,7 +77,7 @@ def test_extra_arrange(hello_world_path) -> None:
     assert result == ""
 
 
-def test_assert_in_block(hello_world_path) -> None:
+def test_assert_in_block(hello_world_path: pathlib.Path) -> None:
     """
     Any assertion that needs the `with` block open, goes after Act and a BL.
     """
@@ -73,19 +91,18 @@ def test_assert_in_block(hello_world_path) -> None:
     assert result == ""
 
 
-def test_pytest_assert_raises_in_block(hello_world_path) -> None:
+def test_pytest_assert_raises_in_block(hello_world_path: pathlib.Path) -> None:
     """
     Checking on a raise in a with block works with Pytest.
     """
     with open(hello_world_path) as f:
-
         with pytest.raises(io.UnsupportedOperation):
             f.write("hello back")
 
         assert f.read() == "Hello World!\n"
 
 
-def test_pytest_assert_raises_on_with(hello_world_path) -> None:
+def test_pytest_assert_raises_on_with(hello_world_path: pathlib.Path) -> None:
     """
     Checking on the raise from a with statement works with Pytest.
     """
@@ -96,7 +113,7 @@ def test_pytest_assert_raises_on_with(hello_world_path) -> None:
     assert "invalid mode" in str(excinfo.value)
 
 
-def test_with_in_assert(hello_world_path) -> None:
+def test_with_in_assert(hello_world_path: pathlib.Path) -> None:
     """
     Using with statement in Assert block is valid
     """

examples/black/test_with_statement_unittest.py

@@ -14,7 +14,6 @@ def test_assert_raises_in_block(self):
         Checking on a raise in a with block works with unittest.
         """
         with open(self.hello_world_path) as f:
-
             with self.assertRaises(io.UnsupportedOperation):
                 f.write("hello back")
 

requirements/examples.in

@@ -1,5 +1,5 @@
 # py37
-black<23
+black
 flake8
 mypy
 pytest

requirements/examples.txt

@@ -4,7 +4,7 @@
 #
 #    pip-compile --output-file=examples.txt examples.in
 #
-black==22.12.0
+black==23.3.0
     # via -r examples.in
 click==8.1.3
     # via black
@@ -29,10 +29,12 @@ mypy-extensions==1.0.0
     #   black
     #   mypy
 packaging==23.1
-    # via pytest
+    # via
+    #   black
+    #   pytest
 pathspec==0.11.1
     # via black
-platformdirs==3.2.0
+platformdirs==3.5.0
     # via black
 pluggy==1.0.0
     # via pytest

requirements/test.in

@@ -5,5 +5,6 @@ isort
 mypy==0.930
 pygments
 pytest
+pytest-icdiff
 restructuredtext-lint
 yapf

requirements/test.txt

@@ -4,16 +4,16 @@
 #
 #    pip-compile --output-file=test.txt test.in
 #
-attrs==22.2.0
-    # via pytest
 docutils==0.19
     # via restructuredtext-lint
 exceptiongroup==1.1.1
     # via pytest
-faker==18.4.0
+faker==18.6.0
     # via -r test.in
 flake8==4.0.1
     # via -r test.in
+icdiff==2.0.6
+    # via pytest-icdiff
 importlib-metadata==4.2.0
     # via
     #   flake8
@@ -29,17 +29,23 @@ mypy==0.930
     # via -r test.in
 mypy-extensions==1.0.0
     # via mypy
-packaging==23.0
+packaging==23.1
     # via pytest
 pluggy==1.0.0
     # via pytest
+pprintpp==0.4.0
+    # via pytest-icdiff
 pycodestyle==2.8.0
     # via flake8
 pyflakes==2.4.0
     # via flake8
-pygments==2.14.0
+pygments==2.15.1
     # via -r test.in
-pytest==7.2.2
+pytest==7.3.1
+    # via
+    #   -r test.in
+    #   pytest-icdiff
+pytest-icdiff==0.6
     # via -r test.in
 python-dateutil==2.8.2
     # via faker
@@ -51,14 +57,15 @@ tomli==2.0.1
     # via
     #   mypy
     #   pytest
+    #   yapf
 typed-ast==1.5.4
     # via mypy
 typing-extensions==4.5.0
     # via
     #   faker
     #   importlib-metadata
     #   mypy
-yapf==0.32.0
+yapf==0.33.0
     # via -r test.in
 zipp==3.15.0
     # via importlib-metadata

src/flake8_aaa/block.py

@@ -5,6 +5,7 @@
 from .exceptions import EmptyBlock
 from .helpers import filter_arrange_nodes, get_first_token, get_last_token
 from .types import LineType
+from .visitors import find_first_child_nodes
 
 _Block = TypeVar('_Block', bound='Block')
 
@@ -38,18 +39,41 @@ def __init__(self, first_line_no: int, last_line_no: int, lt: LineType) -> None:
     def build_act(
         cls: Type[_Block],
         node: ast.stmt,
-        test_func_node: ast.FunctionDef,  # use this in TODO200
-        act_block_style: ActBlockStyle,  # use this in TODO200
+        test_func_node: ast.FunctionDef,
+        act_block_style: ActBlockStyle,
     ) -> _Block:
         """
-        Act block is a single node by default. TODO200
+        Using the provided `node` as Act Node, build the Act Block depending on
+        the `act_block_style`.
+
+        Act blocks are simply a single Act node in default mode. However,
+        "large" Act blocks include the Act node and any context managers that
+        wrap them.
 
         Args:
             node: Act node already found by Function.mark_act()
             test_func_node: Node of test function / method.
-            act_block_style: Currently always DEFAULT.
+            act_block_style: Default Act Blocks are just the Act node. Large
+                Act Blocks can absorb context managers that wrap them.
         """
-        first, last = get_span(node, node)
+        if act_block_style == ActBlockStyle.DEFAULT:
+            first, last = get_span(node, node)
+            return cls(first, last, LineType.act)
+
+        # --- LARGE Act Block behaviour...
+
+        # Walk up the parent nodes of the act node, but only when act node is
+        # the first child. This allows act block to absorb context managers
+        # that have the act node first in their body.
+        child_parent_map = find_first_child_nodes(test_func_node)
+        wrapper_node = node
+        while True:
+            try:
+                wrapper_node = child_parent_map[wrapper_node]
+            except KeyError:
+                break
+
+        first, last = get_span(wrapper_node, node)
         return cls(first, last, LineType.act)
 
     @classmethod

src/flake8_aaa/checker.py

@@ -24,12 +24,15 @@ class Checker:
     name = __short_name__
     version = __version__
 
+    default_config = Config.default_options()
+
     def __init__(self, tree: AST, lines: List[str], filename: str):
         self.tree = tree
         self.lines = lines
         self.filename = filename
         self.ast_tokens: Optional[asttokens.ASTTokens] = None
-        self.config: Config = Config.default_options()
+
+        self.config: Config = self.default_config
 
     @staticmethod
     def add_options(option_manager) -> None:
@@ -56,7 +59,7 @@ def parse_options(cls, option_manager, options: argparse.Namespace, args) -> Non
         Raises:
             UnexpectedConfigValue: When config can't be loaded.
         """
-        cls.config = Config.load_options(options)
+        cls.default_config = Config.load_options(options)
 
     def load(self) -> None:
         self.ast_tokens = asttokens.ASTTokens(''.join(self.lines), tree=self.tree)

src/flake8_aaa/conf.py

@@ -11,7 +11,7 @@
 @enum.unique
 class ActBlockStyle(enum.Enum):
     DEFAULT = 'default'
-    # LARGE = 'large'  # TODO200
+    LARGE = 'large'
 
     @classmethod
     def allowed_values(cls: Type[_ActBlockStyle]) -> List[str]:

src/flake8_aaa/function.py

@@ -177,7 +177,7 @@ def mark_act(self, act_block_style: ActBlockStyle) -> int:
         lines in ``line_markers``.
 
         Args:
-            act_block_style: Currently only DEFAULT. TODO200
+            act_block_style: Passed through to `build_act()` method.
 
         Returns:
             Number of lines covered by the Act block (used for debugging /