reverse-proxy/tasks/fix/logging-test-global-subscriber.md

id, name, status, depends_on, scope, risk, impact, level, review_findings

id	name	status	depends_on	scope	risk	impact	level	review_findings
fix/logging-test-global-subscriber	Fix logging test that conflicts with global tracing subscriber	completed		single	low	isolated	implementation	W9

Description

The test init_creates_log_directory_and_file in src/logging/mod.rs calls init() which sets a global default tracing subscriber. When tests run in parallel, this conflicts with other tests that may also set a subscriber, causing the test to fail with "a global default trace dispatcher has already been set."

Changes Required

src/logging/mod.rs:

• Change init() or the test to use tracing_subscriber::util::SubscriberInitExt::try_init() which returns an error if already set rather than panicking
• Alternatively, use std::sync::OnceLock to guard against double-initialization in tests
• The production code should still use init() (which panics on double-init — that's correct behavior for a production binary), but the test should handle the case where a subscriber is already set

Approach

The cleanest approach is to make init() return Result<()> and use try_init() internally. If initialization fails because a subscriber is already set, return an error rather than panicking. This way:

• Production code: init() is called once at startup; if it fails, that's a real error
• Tests: Can call init() in a test helper and gracefully handle the "already initialized" case

Alternatively, keep init() as-is and only change the test to use try_init() directly.

Acceptance Criteria

• Logging test no longer panics when run in parallel with other tests
• Production init() behavior is unchanged (sets global subscriber)
• All tests pass (including parallel cargo test)
• cargo clippy passes with no warnings

References

• docs/reviews/002-implementation-review.md — W9 finding
• src/logging/mod.rs — init() function and init_creates_log_directory_and_file test

Notes

To be filled by implementation agent

Summary

To be filled on completion