Merge pull request #123 from jamescooke/type-assertions-bug

Fix annotated assignment Act block search

Author: jamescooke

CHANGELOG.rst

@@ -14,6 +14,12 @@ Unreleased_
 See also `latest documentation
 <https://flake8-aaa.readthedocs.io/en/latest/>`_.
 
+Fixed
+.....
+
+* NEEDS CONFIRMATION: Bug preventing type annotated assignment Act blocks from being found `#123
+  <https://github.com/jamescooke/flake8-aaa/pull/123>`_
+
 0.7.1_ - 2019/11/16
 -------------------
 

examples/good_py36_plus/test_type_hints.py

@@ -0,0 +1,20 @@
+def add_one(x: int) -> int:
+    return x + 1
+
+
+# Example from https://github.com/jamescooke/flake8-aaa/issues/122
+
+
+def test_add_one() -> None:
+    """
+    Addition of type hint in act block does not prevent act block being found
+    """
+    # Arrange.
+    data: int = 0
+
+    # Act.
+    result: int = add_one(data)
+
+    # Assert.
+    assert result != data
+    assert result == data + 1

src/flake8_aaa/helpers.py

@@ -87,14 +87,19 @@ def node_is_result_assignment(node: ast.AST) -> bool:
     Returns:
         bool: ``node`` corresponds to the code ``result =``, assignment to the
         ``result `` variable.
-
-    Note:
-        Performs a very weak test that the line starts with 'result =' rather
-        than testing the tokens.
     """
-    # `.first_token` is added by asttokens
-    token = node.first_token  # type: ignore
-    return token.line.strip().startswith('result =')
+    if isinstance(node, ast.Assign):
+        return len(node.targets) == 1 and isinstance(node.targets[0], ast.Name) and node.targets[0].id == "result"
+
+    # py35 has no Annotated Assignment, so work around it...
+    try:
+        ann_assign_cls = getattr(ast, 'AnnAssign')
+    except AttributeError:
+        return False
+
+    if isinstance(node, ann_assign_cls):
+        return node.target.id == "result"  # type: ignore
+    return False
 
 
 def node_is_pytest_raises(node: ast.AST) -> bool:

tests_py36_plus/act_node/__init__.py

@@ -0,0 +1,23 @@
+import pytest
+
+from flake8_aaa.act_node import ActNode
+from flake8_aaa.types import ActNodeType
+
+
+@pytest.mark.parametrize(
+    'code_str, expected_type', [
+        ('result: Thing = do_thing()', ActNodeType.result_assignment),
+        ('result: List[int] = do_thing()', ActNodeType.result_assignment),
+    ]
+)
+def test(expected_type, first_node_with_tokens):
+    """
+    Assert that type-hinted result assignments can be found as act blocks
+    """
+    result: ActNode = ActNode.build(first_node_with_tokens)
+
+    assert isinstance(result, list)
+    assert len(result) == 1
+    assert isinstance(result[0], ActNode)
+    assert result[0].node == first_node_with_tokens
+    assert result[0].block_type == expected_type

tests_py36_plus/act_node/test_build.py

@@ -0,0 +1,17 @@
+import pytest
+
+from flake8_aaa.helpers import node_is_result_assignment
+
+
+@pytest.mark.parametrize(
+    ('code_str', 'expected_result'),
+    [
+        ('result: int = 1', True),
+        ('result: List[int] = [1]', True),
+        ('xresult: int = 1', False),
+    ],
+)
+def test_no(first_node_with_tokens, expected_result):
+    result = node_is_result_assignment(first_node_with_tokens)
+
+    assert result is expected_result