Bump pytest-beartype-tests to 2026.4.26; revert subprocess workaround in ci/test_custom_linters.py

Author: adamtheturtle

ci/test_custom_linters.py

@@ -1,7 +1,5 @@
 """Custom lint tests."""
 
-import subprocess
-import sys
 from pathlib import Path
 
 import pytest
@@ -21,61 +19,52 @@ def _ci_patterns(*, repository_root: Path) -> set[str]:
     return ci_patterns
 
 
+class _CollectPlugin:
+    """Pytest plugin that records the node IDs of collected items."""
+
+    def __init__(self) -> None:
+        """Start with an empty set of collected node IDs."""
+        self.collected: set[str] = set()
+
+    def pytest_itemcollected(self, item: pytest.Item) -> None:
+        """Record each collected item's node ID."""
+        self.collected.add(item.nodeid)
+
+
 @beartype
-def _collect(
-    *, ci_pattern: str, repository_root: Path
-) -> subprocess.CompletedProcess[str]:
-    """Run ``pytest --collect-only`` for ``ci_pattern`` in a fresh
-    subprocess.
-
-    A real subprocess (not ``pytest.main``) is used so that plugin state
-    -- notably ``pytest-beartype-tests`` re-wrapping the same test
-    functions -- does not accumulate across iterations and trigger
-    ``Cannot stringify annotation containing string formatting`` under
-    Python 3.14 deferred annotations.
-    See https://github.com/adamtheturtle/pytest-beartype-tests/issues/30.
-    """
-    return subprocess.run(
+def _tests_from_pattern(*, ci_pattern: str) -> set[str]:
+    """From a CI pattern, get all tests ``pytest`` would collect."""
+    plugin = _CollectPlugin()
+    pytest.main(
         args=[
-            sys.executable,
-            "-m",
-            "pytest",
             "-q",
             "--collect-only",
             # Disable pytest-retry to avoid:
             # ```
             # ValueError: no option named 'filtered_exceptions'
             # ```
+            # which causes the nested run to exit with INTERNAL_ERROR
+            # before any items are collected.
             "-p",
             "no:pytest-retry",
+            # Disable pytest-beartype-tests to avoid
+            # https://github.com/beartype/beartype/issues/637 — wrapping
+            # collected items with @beartype installs a buggy
+            # __annotate_beartype__ closure on the underlying test
+            # function, which crashes a subsequent nested collection on
+            # Python 3.14.
+            "-p",
+            "no:pytest_beartype_tests",
             # Disable warnings to avoid many instances of:
             # ```
             # Unknown config option: retry_delay
             # ```
             "--disable-warnings",
             ci_pattern,
         ],
-        check=False,
-        cwd=repository_root,
-        capture_output=True,
-        text=True,
+        plugins=[plugin],
     )
-
-
-@beartype
-def _tests_from_pattern(*, ci_pattern: str, repository_root: Path) -> set[str]:
-    """From a CI pattern, get all tests ``pytest`` would collect."""
-    result = _collect(
-        ci_pattern=ci_pattern,
-        repository_root=repository_root,
-    )
-    tests: set[str] = set()
-    for line in result.stdout.splitlines():
-        # We filter empty lines and lines which look like
-        # "9 tests collected in 0.01s".
-        if line and "collected in" not in line:
-            tests.add(line)
-    return tests
+    return plugin.collected
 
 
 def test_ci_patterns_valid(request: pytest.FixtureRequest) -> None:
@@ -84,45 +73,53 @@ def test_ci_patterns_valid(request: pytest.FixtureRequest) -> None:
     test in
     the test suite.
     """
-    repository_root = request.config.rootpath
-    ci_patterns = _ci_patterns(repository_root=repository_root)
+    ci_patterns = _ci_patterns(repository_root=request.config.rootpath)
 
     for ci_pattern in ci_patterns:
-        result = _collect(
-            ci_pattern=ci_pattern,
-            repository_root=repository_root,
-        )
-        message = (
-            f'"{ci_pattern}" does not match any tests.\n'
-            f"stdout:\n{result.stdout}\nstderr:\n{result.stderr}"
+        collect_only_result = pytest.main(
+            args=[
+                "--collect-only",
+                ci_pattern,
+                # Disable pytest-retry to avoid:
+                # ```
+                # ValueError: no option named 'filtered_exceptions'
+                # ````
+                "-p",
+                "no:pytest-retry",
+                # Disable pytest-beartype-tests to avoid
+                # https://github.com/beartype/beartype/issues/637 —
+                # wrapping collected items with @beartype installs a
+                # buggy __annotate_beartype__ closure on the underlying
+                # test function, which crashes a subsequent nested
+                # collection on Python 3.14.
+                "-p",
+                "no:pytest_beartype_tests",
+                # Disable warnings to avoid many instances of:
+                # ```
+                # Unknown config option: retry_delay
+                # ```
+                "--disable-warnings",
+            ],
         )
-        assert result.returncode == 0, message
+
+        message = f'"{ci_pattern}" does not match any tests.'
+        assert collect_only_result == 0, message
 
 
 def test_tests_collected_once(request: pytest.FixtureRequest) -> None:
     """Each test in the test suite is collected exactly once.
 
     This does not necessarily mean that they are run - they may be skipped.
     """
-    repository_root = request.config.rootpath
-    ci_patterns = _ci_patterns(repository_root=repository_root)
-    all_tests = _tests_from_pattern(
-        ci_pattern=".",
-        repository_root=repository_root,
-    )
+    ci_patterns = _ci_patterns(repository_root=request.config.rootpath)
+    all_tests = _tests_from_pattern(ci_pattern=".")
     assert all_tests
     tests_to_patterns: dict[str, set[str]] = {}
 
     for pattern in ci_patterns:
-        tests = _tests_from_pattern(
-            ci_pattern=pattern,
-            repository_root=repository_root,
-        )
+        tests = _tests_from_pattern(ci_pattern=pattern)
         for test in tests:
-            if test in tests_to_patterns:
-                tests_to_patterns[test].add(pattern)
-            else:
-                tests_to_patterns[test] = {pattern}
+            tests_to_patterns.setdefault(test, set()).add(pattern)
 
     for test_name, patterns in tests_to_patterns.items():
         message = (

pyproject.toml

@@ -76,7 +76,7 @@ optional-dependencies.dev = [
     "pyright==1.1.409",
     "pyroma==5.0.1",
     "pytest==9.0.3",
-    "pytest-beartype-tests==2026.4.20",
+    "pytest-beartype-tests==2026.4.26",
     "pytest-retry==1.7.0",
     "pytest-xdist==3.8.0",
     "pyyaml==6.0.3",