Fix coverage for conformance subprocesses

conformance/test/_cov_embed.py

@@ -0,0 +1,156 @@
+# Includes work from:
+#
+# The MIT License
+#
+# Copyright (c) 2010 Meme Dough
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+# THE SOFTWARE.
+
+# Copied from pytest-cov 6.3.0's https://github.com/pytest-dev/pytest-cov/blob/v6.3.0/src/pytest_cov/embed.py
+# It was removed to rely on coverage.py's patching of subprocess, etc commands in Python, but because we have
+# a Go command in the middle, that doesn't work for us and we go ahead and vendor in and call the embed code
+# ourselves.
+
+"""Activate coverage at python startup if appropriate.
+
+The python site initialisation will ensure that anything we import
+will be removed and not visible at the end of python startup.  However
+we minimise all work by putting these init actions in this separate
+module and only importing what is needed when needed.
+
+For normal python startup when coverage should not be activated the pth
+file checks a single env var and does not import or call the init fn
+here.
+
+For python startup when an ancestor process has set the env indicating
+that code coverage is being collected we activate coverage based on
+info passed via env vars.
+"""
+
+from __future__ import annotations
+
+import atexit
+import contextlib
+import os
+import signal
+
+import coverage
+
+_active_cov = None
+
+
+def init():
+    # Only continue if ancestor process has set everything needed in
+    # the env.
+    global _active_cov  # noqa: PLW0603
+
+    cov_source = os.environ.get("COV_CORE_SOURCE")
+    cov_config = os.environ.get("COV_CORE_CONFIG")
+    cov_datafile = os.environ.get("COV_CORE_DATAFILE")
+    cov_branch = True if os.environ.get("COV_CORE_BRANCH") == "enabled" else None
+    cov_context = os.environ.get("COV_CORE_CONTEXT")
+
+    if cov_datafile:
+        assert cov_source is not None
+        if _active_cov:
+            cleanup()
+
+        # Determine all source roots.
+        cov_source = None if cov_source in os.pathsep else cov_source.split(os.pathsep)
+        if cov_config == os.pathsep:
+            cov_config = True
+
+        # Activate coverage for this process.
+        cov = _active_cov = coverage.Coverage(
+            source=cov_source,
+            branch=cov_branch,
+            data_suffix=True,
+            config_file=cov_config or False,
+            auto_data=True,
+            data_file=cov_datafile,
+        )
+        cov.load()
+        cov.start()
+        if cov_context:
+            cov.switch_context(cov_context)
+        cov._warn_no_data = False
+        cov._warn_unimported_source = False
+        cov._warn_preimported_source = False
+        return cov
+    return None
+
+
+def _cleanup(cov):
+    if cov is not None:
+        cov.stop()
+        cov.save()
+        cov._auto_save = False  # prevent autosaving from cov._atexit in case the interpreter lacks atexit.unregister
+        with contextlib.suppress(Exception):
+            atexit.unregister(cov._atexit)
+
+
+def cleanup():
+    global _active_cov  # noqa: PLW0603
+    global _cleanup_in_progress  # noqa: PLW0603
+    global _pending_signal  # noqa: PLW0603
+
+    _cleanup_in_progress = True
+    _cleanup(_active_cov)
+    _active_cov = None
+    _cleanup_in_progress = False
+    if _pending_signal:
+        pending_signal = _pending_signal
+        _pending_signal = None
+        _signal_cleanup_handler(*pending_signal)
+
+
+_previous_handlers = {}
+_pending_signal = None
+_cleanup_in_progress = False
+
+
+def _signal_cleanup_handler(signum, frame):
+    global _pending_signal  # noqa: PLW0603
+    if _cleanup_in_progress:
+        _pending_signal = signum, frame
+        return
+    cleanup()
+    _previous_handler = _previous_handlers.get(signum)
+    if _previous_handler == signal.SIG_IGN:
+        return
+    if _previous_handler and _previous_handler is not _signal_cleanup_handler:
+        _previous_handler(signum, frame)
+    elif signum == signal.SIGTERM:
+        os._exit(128 + signum)
+    elif signum == signal.SIGINT:
+        raise KeyboardInterrupt
+
+
+def cleanup_on_signal(signum):
+    previous = signal.getsignal(signum)
+    if previous is not _signal_cleanup_handler:
+        _previous_handlers[signum] = previous
+        signal.signal(signum, _signal_cleanup_handler)
+
+
+def cleanup_on_sigterm():
+    cleanup_on_signal(signal.SIGTERM)
+
+
+init()

conformance/test/_util.py

@@ -1,7 +1,12 @@
 from __future__ import annotations
 
 import asyncio
+import os
 import sys
+from typing import TYPE_CHECKING
+
+if TYPE_CHECKING:
+    from coverage import Coverage
 
 VERSION_CONFORMANCE = "v1.0.5"
 
@@ -30,3 +35,22 @@ def maybe_patch_args_with_debug(args: list[str]) -> list[str]:
         return _pydev_bundle.pydev_monkey.patch_args(args)
     except Exception:
         return args
+
+
+def coverage_env(cov: Coverage | None) -> dict[str, str] | None:
+    if cov is None:
+        return None
+    env: dict[str, str] = {**os.environ}
+    # cov.config.source only contains . but we need .. too.
+    # It should be fine to just hard-code this.
+    env["COV_CORE_SOURCE"] = os.pathsep.join((".", ".."))
+    if cov.config.config_file:
+        env["COV_CORE_CONFIG"] = cov.config.config_file
+    if cov.config.data_file:
+        env["COV_CORE_DATAFILE"] = cov.config.data_file
+    if cov.config.branch:
+        env["COV_CORE_BRANCH"] = "enabled"
+    if cov.config.context:
+        env["COV_CORE_CONTEXT"] = cov.config.context
+
+    return env

conformance/test/client.py

@@ -10,6 +10,7 @@
 import traceback
 from typing import TYPE_CHECKING, Literal, TypeVar, get_args
 
+import _cov_embed  # noqa: F401
 from _util import create_standard_streams
 from gen.connectrpc.conformance.v1.client_compat_pb2 import (
     ClientCompatRequest,

conformance/test/server.py

@@ -13,6 +13,8 @@
 from tempfile import NamedTemporaryFile
 from typing import TYPE_CHECKING, Literal, TypeVar, get_args
 
+# Needs to run before importing from connectrpc
+import _cov_embed  # noqa: F401
 from _util import create_standard_streams
 from gen.connectrpc.conformance.v1.config_pb2 import Code as ConformanceCode
 from gen.connectrpc.conformance.v1.server_compat_pb2 import (

conformance/test/test_client.py

@@ -3,10 +3,14 @@
 import subprocess
 import sys
 from pathlib import Path
+from typing import TYPE_CHECKING
 
 import pytest
 
-from ._util import VERSION_CONFORMANCE, maybe_patch_args_with_debug
+from ._util import VERSION_CONFORMANCE, coverage_env, maybe_patch_args_with_debug
+
+if TYPE_CHECKING:
+    from coverage import Coverage
 
 _current_dir = Path(__file__).parent
 _client_py_path = str(_current_dir / "client.py")
@@ -19,7 +23,7 @@
 ]
 
 
-def test_client_sync() -> None:
+def test_client_sync(cov: Coverage | None) -> None:
     args = maybe_patch_args_with_debug(
         [sys.executable, _client_py_path, "--mode", "sync"]
     )
@@ -40,12 +44,13 @@ def test_client_sync() -> None:
         capture_output=True,
         text=True,
         check=False,
+        env=coverage_env(cov),
     )
     if result.returncode != 0:
         pytest.fail(f"\n{result.stdout}\n{result.stderr}")
 
 
-def test_client_async() -> None:
+def test_client_async(cov: Coverage | None) -> None:
     args = maybe_patch_args_with_debug(
         [sys.executable, _client_py_path, "--mode", "async"]
     )
@@ -65,6 +70,7 @@ def test_client_async() -> None:
         capture_output=True,
         text=True,
         check=False,
+        env=coverage_env(cov),
     )
     if result.returncode != 0:
         pytest.fail(f"\n{result.stdout}\n{result.stderr}")

conformance/test/test_server.py

@@ -4,10 +4,14 @@
 import subprocess
 import sys
 from pathlib import Path
+from typing import TYPE_CHECKING
 
 import pytest
 
-from ._util import VERSION_CONFORMANCE, maybe_patch_args_with_debug
+from ._util import VERSION_CONFORMANCE, coverage_env, maybe_patch_args_with_debug
+
+if TYPE_CHECKING:
+    from coverage import Coverage
 
 _current_dir = Path(__file__).parent
 _server_py_path = str(_current_dir / "server.py")
@@ -40,7 +44,7 @@ def macos_raise_ulimit():
 
 
 @pytest.mark.parametrize("server", ["gunicorn", "pyvoy"])
-def test_server_sync(server: str) -> None:
+def test_server_sync(server: str, cov: Coverage) -> None:
     args = maybe_patch_args_with_debug(
         [sys.executable, _server_py_path, "--mode", "sync", "--server", server]
     )
@@ -67,13 +71,14 @@ def test_server_sync(server: str) -> None:
         capture_output=True,
         text=True,
         check=False,
+        env=coverage_env(cov),
     )
     if result.returncode != 0:
         pytest.fail(f"\n{result.stdout}\n{result.stderr}")
 
 
 @pytest.mark.parametrize("server", ["daphne", "pyvoy", "uvicorn"])
-def test_server_async(server: str) -> None:
+def test_server_async(server: str, cov: Coverage) -> None:
     args = maybe_patch_args_with_debug(
         [sys.executable, _server_py_path, "--mode", "async", "--server", server]
     )
@@ -117,6 +122,7 @@ def test_server_async(server: str) -> None:
         capture_output=True,
         text=True,
         check=False,
+        env=coverage_env(cov),
     )
     if result.returncode != 0:
         pytest.fail(f"\n{result.stdout}\n{result.stderr}")

pyproject.toml

@@ -69,6 +69,7 @@ build-backend = "uv_build"
 [tool.uv]
 resolution = "lowest-direct"
 constraint-dependencies = [
+    "coverage==7.13.2",
     "pytest==9.0.2",
     "pytest-asyncio==1.3.0",
     "pytest-cov==7.0.0",
@@ -234,7 +235,7 @@ exclude = [
     # See https://github.com/grpc/grpc/issues/39555
     "**/*_pb2_grpc.py",
 
-    # TODO: Work out the import issues to allow it to work.
+    # TODO: Work out the import issues to allow it to work.p
     "conformance/**",
 ]