fix(test): isolate usage-log fixtures from the real OpenCodex home

[Yuxin-Qiao]

Summary

• tests/management-api-logs-metrics.test.ts exercises GET /api/logs display metrics through addRequestLog, which persists every row to usage.jsonl. Unlike its sibling suites that also persist (usage-failure-persistence.test.ts, api-key-attribution.test.ts), it did not redirect OPENCODEX_HOME itself and relied entirely on the bunfig.toml preload (tests/preload.ts).
• The preload only loads when Bun discovers bunfig.toml from the current directory. Running bun test <absolute path> from outside the repo (agent/IDE pattern) skips it, and the fixture rows (ok-a/ok-b/fail, no-such-model, unpriced-model, combo/my-combo, ...) are appended to the developer's real ~/.opencodex/usage.jsonl. The GUI Usage page then renders never-used models with real token counts.
• This change adds a per-test scratch OPENCODEX_HOME (mkdtemp, restored and cleaned in afterEach), matching the established pattern in the two sibling suites.

Reproduction before the fix

$ cd ~ && bun test /path/to/repo/tests/management-api-logs-metrics.test.ts
$ rg '"requestId":"ok-a"' ~/.opencodex/usage.jsonl   # fixture row now in the real log

Verification

• Reproduced against a scratch OPENCODEX_HOME: 11 fixture rows were written before the fix.
• After the fix, the same foreign-cwd invocation leaves the real usage.jsonl untouched.
• bun run typecheck and bun run privacy:scan pass.
• Focused suites (usage-summary, usage-log, request-log, usage-cost, management-api-logs-metrics) pass: 147 tests; this file is 9/9 in the full suite.
• Full suite on this branch is green except 10 management-provider-validation.test.ts cases that fail only in this dev environment because chatgpt.com resolves to a non-global address (write-time DNS/SSRF gate returns 400); upstream CI for dev is green.

Summary by CodeRabbit

• Tests
  • Improved test isolation by using temporary configuration directories for each test.
  • Added cleanup and environment restoration after tests complete.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

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📥 Commits

Reviewing files that changed from the base of the PR and between 6712887 and 4b6532b.

📒 Files selected for processing (1)

• tests/management-api-logs-metrics.test.ts

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📝 Walkthrough

Walkthrough

The test setup creates a temporary OPENCODEX_HOME directory before each test. Teardown restores the previous environment value, clears request logs, and removes the temporary directory.

Changes

Management API test isolation

Layer / File(s)	Summary
Temporary OPENCODEX_HOME lifecycle tests/management-api-logs-metrics.test.ts	The test imports filesystem, OS, and path utilities. Each test receives a temporary OPENCODEX_HOME; teardown restores the prior environment, clears request logs, and removes the directory.

Estimated code review effort: 2 (Simple) | ~10 minutes

Suggested reviewers: wibias, ingwannu, lidge-jun

🚥 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 isolating usage-log fixtures from the real OpenCodex home.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
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 unit tests (beta)

• Create PR with unit tests

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