fix(tests): hermetic HOME for unit tests on Windows runner

[danielmeppiel]

TL;DR

The post-tag CI/CD Pipeline run on v0.13.0 (25660187642) failed Windows unit tests with 57 failures:

• 56: RuntimeError: Could not determine home directory from Path.home() in tests/unit/test_runtime_manager.py and tests/unit/test_runtime_detection.py.
• 1: test_update_command_respects_disabled_policy -- requests.get called once when it should not have been.

Both were latent test-infra issues exposed by GitHub redirecting windows-latest from windows-2025 to windows-2025-vs2026. No product code change.

Problem

1. Path.home() on the new Windows image

Path.home() on Windows reads USERPROFILE first, then HOMEDRIVE+HOMEPATH. The windows-2025-vs2026 image does not seed any of these for pytest worker subprocesses. Any unit test that touches Path.home() (directly or via get_user_runtime_dir() etc.) raises.

2. Missed mock in disabled-self-update test

apm_cli/commands/_helpers.py does from ..update_policy import ... is_self_update_enabled, rebinding the symbol locally. _check_and_notify_updates() runs on every cli() invocation. The test only patched apm_cli.commands.self_update.is_self_update_enabled, leaving the _helpers reference live. On Linux xdist workers an earlier test primed ~/.cache/apm/last_version_check so should_check_for_updates() skipped the network call; Windows workers were cold, so requests.get fired.

Fix

1. tests/unit/conftest.py (new) -- session-scoped autouse _hermetic_home fixture pins Path.home() to a tmp dir via tmp_path_factory.mktemp. Sets HOME on POSIX and USERPROFILE/HOMEDRIVE/HOMEPATH on Windows. Restores prior values on teardown. Per-test monkeypatch.setenv fixtures (_set_home etc.) keep working for their scope.
2. tests/unit/test_update_command.py -- stack a second @patch("apm_cli.commands._helpers.is_self_update_enabled", return_value=False) on test_update_command_respects_disabled_policy and add the matching mock arg.

Validation

Ran locally on macOS:

uv run --extra dev pytest tests/unit tests/test_console.py -n auto --dist worksteal -q
# 8281 passed, 29 subtests passed in 70.94s

Lint mirror clean:

uv run --extra dev ruff check src/ tests/    # All checks passed!
uv run --extra dev ruff format --check src/ tests/   # 746 files already formatted

Cannot reproduce the USERPROFILE drift on macOS, but the conftest fix unifies behaviour with the existing per-test _set_home helper at tests/unit/integration/test_scope_integration.py:25-40, so the Windows runner will now see a stable Path.home() for every unit test.

How to test

Triggered on push to fix/windows-home-runner; the merge will re-trigger the CI/CD Pipeline job on Windows after we re-tag v0.13.0.

[Copilot]

Pull request overview

This PR fixes Windows CI unit test failures by making Path.home() deterministic in unit tests and by correctly patching an import-bound is_self_update_enabled() symbol so the disabled-self-update test cannot accidentally hit the network.

Changes:

• Add a session-scoped autouse unit-test fixture that sets a hermetic HOME/USERPROFILE (and related Windows vars) for the duration of tests/unit.
• Fix test_update_command_respects_disabled_policy by also patching apm_cli.commands._helpers.is_self_update_enabled.
• Add a changelog entry under Unreleased.

Show a summary per file

File	Description
tests/unit/conftest.py	Adds session-wide hermetic HOME environment setup so Path.home() works reliably (including on Windows runners).
tests/unit/test_update_command.py	Ensures the disabled-self-update test patches the correct import binding to prevent unintended network calls.
CHANGELOG.md	Documents the test-infra fix under Unreleased.

Copilot's findings

• Files reviewed: 3/3 changed files
• Comments generated: 1