Respect pytest config python_files when identifying pytest test modules

Author: davidfritzsche

README.md

@@ -34,20 +34,25 @@ option `-p no:mypy-testing`.
 # Writing Mypy Output Test Cases
 
 A mypy test case is a top-level functions decorated with
-`@pytest.mark.mypy_testing` in a file name `test_*.py` or
-`test_*.mypy-testing`.  Note that we use the Python
+`@pytest.mark.mypy_testing` in a file named `*.mypy-testing` or in a
+pytest test module.  `pytest-mypy-testing` follows the pytest logic in
+identifying test modules and respects the
+[`python_files`](https://docs.pytest.org/en/latest/reference.html#confval-python_files)
+config value.
+
+Note that ``pytest-mypy-testing`` uses the Python
 [ast](https://docs.python.org/3/library/ast.html) module to parse
-candidate files and do not import any file, i.e., the decorator must
+candidate files and does not import any file, i.e., the decorator must
 be exactly named `@pytest.mark.mypy_testing`.
 
-In a `test_*.py` file you may combine both regular pytest test
-functions and mypy test functions. A single function can even be both.
+In a pytest test module file you may combine both regular pytest test
+functions and mypy test functions. A single function can be both.
 
 Example: A simple mypy test case could look like this:
 
 ``` python
 @pytest.mark.mypy_testing
-def mypy_test_invalid_assginment():
+def mypy_test_invalid_assginment() -> None:
     foo = "abc"
     foo = 123  # E: Incompatible types in assignment (expression has type "int", variable has type "str")
 ```
@@ -81,8 +86,33 @@ decorators are extracted from the ast.
 # Development
 
 * Create and activate a Python virtual environment.
-* Install development dependencies by calling `pip install -U -r requirements.txt`.
-* Start developing
+* Install development dependencies by calling `python -m pip install
+  -U -r requirements.txt`.
+* Start developing.
 * To run all tests with [tox](https://tox.readthedocs.io/en/latest/),
   Python 3.6, 3.7 and 3.8 must be available. You might want to look
   into using [pyenv](https://github.com/pyenv/pyenv).
+
+
+# Changelog
+
+## v0.0.7
+
+* Fix `PYTEST_VERSION_INFO` - by [@blueyed](https://github.com/blueyed) (#8)
+* Always pass `--check-untyped-defs` to mypy (#11)
+* Respect pytest config `python_files` when identifying pytest test modules (#12)
+
+## v0.0.6 - add pytest 5.4 support
+
+* Update the plugin to work with pytest 5.4 (#7)
+
+## v0.0.5 - CI improvements
+
+* Make invoke tasks work (partially) on Windows (#6)
+* Add an invoke task to run tox environments by selecting globs (e.g.,
+  `inv tox -e py-*`) (#6)
+* Use coverage directly for code coverage to get more consistent
+  parallel run results (#6)
+* Use flit fork dflit to make packaging work with `LICENSES` directory
+  (#6)
+* Bump dependencies (#6)

src/pytest_mypy_testing/parser.py

@@ -103,7 +103,7 @@ def generate_per_line_token_lists(source: str,) -> Iterator[List[tokenize.TokenI
         i += 1
 
 
-def parse_file(filename: str) -> MypyTestFile:
+def parse_file(filename: str, config) -> MypyTestFile:
     """Parse *filename* and return information about mypy test cases."""
     filename = os.path.abspath(filename)
     with open(filename, "r", encoding="utf-8") as f:

src/pytest_mypy_testing/plugin.py

@@ -109,7 +109,7 @@ def __init__(
             config = getattr(parent, "config", None)
         super().__init__(fspath, parent, config, session, nodeid)
         self.add_marker("mypy")
-        self.mypy_file = parse_file(self.fspath)
+        self.mypy_file = parse_file(self.fspath, config=config)
         self._mypy_result: Optional[MypyResult] = None
 
     @classmethod
@@ -186,33 +186,40 @@ def _run_mypy(self, filename: str) -> MypyResult:
 
 
 def pytest_collect_file(path: LocalPath, parent):
-    import builtins
-
-    # Add a reveal_type function to the builtins module
-    if not hasattr(builtins, "reveal_type"):
-        setattr(builtins, "reveal_type", lambda x: x)
-
-    if path.ext not in (".mypy-testing", ".py"):
-        return None  # pragma: no cover
-    if not path.basename.startswith("test_"):
-        return None  # pragma: no cover
-
-    file = PytestMypyFile.from_parent(parent=parent, fspath=path)
-
-    if file.mypy_file.items:
-        return file
-    else:
-        return None
+    if path.ext == ".mypy-testing" or _is_pytest_test_file(path, parent):
+        file = PytestMypyFile.from_parent(parent=parent, fspath=path)
+        if file.mypy_file.items:
+            return file
+    return None
+
+
+def _is_pytest_test_file(path: LocalPath, parent):
+    """Return `True` if *path* is considered to be a pytest test file."""
+    # Based on _pytest/python.py::pytest_collect_file
+    fn_patterns = parent.config.getini("python_files") + ["__init__.py"]
+    return path.ext == ".py" and (
+        parent.session.isinitpath(path) or any(path.fnmatch(pat) for pat in fn_patterns)
+    )
 
 
 def pytest_configure(config):
     """
     Register a custom marker for MypyItems,
     and configure the plugin based on the CLI.
     """
+    _add_reveal_type_to_builtins()
+
     config.addinivalue_line(
         "markers", "mypy_testing: mark functions to be used for mypy testing."
     )
     config.addinivalue_line(
         "markers", "mypy: mark mypy tests. Do not add this marker manually!"
     )
+
+
+def _add_reveal_type_to_builtins():
+    # Add a reveal_type function to the builtins module
+    import builtins
+
+    if not hasattr(builtins, "reveal_type"):
+        setattr(builtins, "reveal_type", lambda x: x)

tests/test_parser.py

@@ -4,8 +4,10 @@
 import ast
 import sys
 from tokenize import COMMENT, ENDMARKER, NAME, NEWLINE, NL, TokenInfo
+from unittest.mock import Mock
 
 import pytest
+from _pytest.config import Config
 
 from pytest_mypy_testing.parser import (
     MypyTestItem,
@@ -87,4 +89,5 @@ def test_mypy_bar():
     )
 
     monkeypatch.setattr(sys, "version_info", (3, 7, 5))
-    parse_file(str(path))
+    config = Mock(spec=Config)
+    parse_file(str(path), config)

tests/test_plugin.py

@@ -34,7 +34,10 @@ def mk_dummy_parent(tmp_path, filename, content=""):
 
     config = Mock(spec=Config)
     config.rootdir = str(tmp_path)
-    session = SimpleNamespace(config=config, _initialpaths=[])
+    config.getini.return_value = ["test_*.py", "*_test.py"]
+    session = SimpleNamespace(
+        config=config, isinitpath=lambda p: True, _initialpaths=[]
+    )
     parent = SimpleNamespace(
         config=config,
         session=session,