test(host-runtime): write test keystores to the temp dir, not the real one

[Virgile-pct]

Follow-up to #1847, which stopped this suite from deleting the node key and measured the owner keystore as still outstanding. This closes that one.

What happens today

Six tests write their keystore fixture to default_keystore_path():

let temp = tempfile::tempdir().unwrap();
let _home_guard = HomeEnvGuard::set(temp.path());
let owner = OwnerKeypair::generate();
let keystore_path = default_keystore_path().unwrap();   // the real home
save_keystore(&keystore_path, &owner, None, true).unwrap();

default_keystore_path() resolves through dirs::home_dir() in mesh-llm-identity and has no test override. The #[cfg(test)] hook that protects the node key lives in host-runtime, so it cannot reach a path resolved inside another crate, and HomeEnvGuard has no effect on it.

Measured on Windows 11 against 3f4f1c35a, one full cargo test -p mesh-llm-host-runtime, comparing ~/.mesh-llm/owner-keystore.json before and after: same size, same fifteen fields, six of them different. owner_id, created_at, and both the signing and encryption key pairs. The developer's owner identity is replaced by running the suite.

What this changes

Each of the six call sites already had a tempfile::tempdir() on the line above, and each already handed the path to state.set_owner_key_path(). The default location was only ever somewhere to put the fixture; the code under test reads whatever path it is given. They now write into that temp directory.

Six lines, plus one import that became unused.

Measured effect

Same box, same command, comparing ~/.mesh-llm before and after:

	#1847	this branch
node key	unchanged	unchanged
owner-keystore.json	rewritten	unchanged
passed / failed	3457 / 17	3457 / 17

The 17 failures are identical to the parent commit, compared by diffing both complete sorted lists rather than by eye. No new failures, and none of the six tests changed state: they passed before and still pass, they were simply passing while overwriting the developer's identity.

What still remains

The skippy hash cache still writes into ~/.mesh-llm/cache/hashes, six files per run, because tests leave MESH_LLM_HASH_CACHE_DIR unset and hash_cache.rs falls back to the home. That is a cache rather than identity material, so I left it out of this branch rather than mixing a third concern in. Happy to take it next if you want the suite to touch nothing at all.

Gates

• cargo test -p mesh-llm-host-runtime: 3457 passed, 17 failed, as above.
• cargo fmt --all --check: clean.
• cargo clippy -p mesh-llm-host-runtime --all-targets: 8 lints, and the complete sorted set is identical to main.
• cargo run -p xtask -- repo-consistency no-console-print: passed.
• scripts/check-env-mutation-contract.py and python -m unittest scripts.tests.test_env_mutation_contract: passed, census unchanged at 234 sites.

Summary by CodeRabbit

• Tests
  • Updated API tests to use temporary keystore locations consistently.
  • Improved test isolation for configuration diagnostics and control-plane scenarios.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Advanced

Run ID: ddd66524-e56a-4548-98a8-dc974126ed67

📥 Commits

Reviewing files that changed from the base of the PR and between 3f4f1c3 and 1cadd28.

📒 Files selected for processing (3)

• crates/mesh-llm-host-runtime/src/api/tests/apply_config_diagnostics.rs
• crates/mesh-llm-host-runtime/src/api/tests/control_plane.rs
• crates/mesh-llm-host-runtime/src/api/tests/mod.rs

Included review availability: Your plan provides up to 8 included reviews per hour; 7 remain after this review.

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📝 Walkthrough

Walkthrough

API tests now save owner keystores under temporary directories instead of using the default keystore path. The test module removes the unused default_keystore_path import.

Changes

Temporary keystore test updates

Layer / File(s)	Summary
Use temporary owner keystore paths crates/mesh-llm-host-runtime/src/api/tests/apply_config_diagnostics.rs, crates/mesh-llm-host-runtime/src/api/tests/control_plane.rs, crates/mesh-llm-host-runtime/src/api/tests/mod.rs	Diagnostic and control-plane tests use owner-keystore.json within temporary directories. The API test imports retain only OwnerKeypair and save_keystore.

Priority: ⬇️ Low

Estimated code review effort: 1 (Trivial) | ~5 minutes

Change: Bug fix

Suggested reviewers: ndizazzo

Merge Risk: ⚪ Minimal · up to e400c

The change prevents these tests from modifying the developer’s real owner keystore without altering their intended behavior.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and concisely describes the main change: test keystores now use temporary directories instead of the real keystore path.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 6 functions across 3 files.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix/windows-test-keystore

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[i386]

Reviewed the synchronized exact head. Windows keystore tests use isolated temporary paths without changing production behavior; the full host-runtime package suite passes locally.