realpython · dmtucker · Dec 18, 2022 · Dec 11, 2022 · Nov 12, 2022
diff --git a/.github/workflows/validation.yml b/.github/workflows/validation.yml
@@ -2,13 +2,13 @@ name: Validation
 on: [push, pull_request]
 jobs:
   build:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     strategy:
       matrix:
         python-version: ["3.6", "3.7", "3.8", "3.9", "3.10", "3.11"]
     steps:
-    - uses: actions/checkout@v2
-    - uses: actions/setup-python@v2
+    - uses: actions/checkout@v3
+    - uses: actions/setup-python@v4
       with:
         python-version: ${{ matrix.python-version }}
     - run: python -m pip install --upgrade tox-gh-actions

diff --git a/changelog.md b/changelog.md
@@ -1,5 +1,8 @@
 # Changelog
 
+## [0.10.3](https://github.com/dbader/pytest-mypy/milestone/21)
+* Stop failing if mypy only produces notes.
+
 ## [0.10.2](https://github.com/dbader/pytest-mypy/milestone/20)
 * Update and loosen [build-system] requirements.
 

diff --git a/src/pytest_mypy.py b/src/pytest_mypy.py
@@ -5,6 +5,7 @@
 from pathlib import Path
 from tempfile import NamedTemporaryFile
 from typing import Dict, List, Optional, TextIO
+import warnings
 
 import attr
 from filelock import FileLock  # type: ignore
@@ -202,7 +203,13 @@ def runtest(self):
         abspath = os.path.abspath(str(self.fspath))
         errors = results.abspath_errors.get(abspath)
         if errors:
-            raise MypyError(file_error_formatter(self, results, errors))
+            if not all(
+                error.partition(":")[2].partition(":")[0].strip() == "note"
+                for error in errors
+            ):
+                raise MypyError(file_error_formatter(self, results, errors))
+            # This line cannot be easily covered on mypy < 0.990:
+            warnings.warn("\n" + "\n".join(errors), MypyWarning)  # pragma: no cover
 
     def reportinfo(self):
         """Produce a heading for the test report."""
@@ -314,6 +321,10 @@ class MypyError(Exception):
     """
 
 
+class MypyWarning(pytest.PytestWarning):
+    """A non-failure message regarding the mypy run."""
+
+
 def pytest_terminal_summary(terminalreporter, config):
     """Report stderr and unrecognized lines from stdout."""
     try:

diff --git a/tests/test_pytest_mypy.py b/tests/test_pytest_mypy.py
@@ -98,6 +98,33 @@ def pyfunc(x: int) -> str:
     assert result.ret != 0
 
 
+def test_mypy_annotation_unchecked(testdir, xdist_args):
+    """Verify that annotation-unchecked warnings do not manifest as an error."""
+    testdir.makepyfile(
+        """
+            def pyfunc(x):
+                y: int = 2
+                return x * y
+        """,
+    )
+    result = testdir.runpytest_subprocess(*xdist_args)
+    result.assert_outcomes()
+    result = testdir.runpytest_subprocess("--mypy", *xdist_args)
+    mypy_file_checks = 1
+    mypy_status_check = 1
+    mypy_checks = mypy_file_checks + mypy_status_check
+    outcomes = {"passed": mypy_checks}
+    # mypy doesn't emit annotation-unchecked warnings until 0.990:
+    min_mypy_version = Version("0.990")
+    if MYPY_VERSION >= min_mypy_version and PYTEST_VERSION >= Version("7.0"):
+        # assert_outcomes does not support `warnings` until 7.x.
+        outcomes["warnings"] = 1
+    result.assert_outcomes(**outcomes)
+    if MYPY_VERSION >= min_mypy_version:
+        result.stdout.fnmatch_lines(["*MypyWarning*"])
+    assert result.ret == 0
+
+
 def test_mypy_ignore_missings_imports(testdir, xdist_args):
     """
     Verify that --mypy-ignore-missing-imports