[Fix] Router code coverage CI failure for health check filter tests

[yuneng-berri]

Relevant issues

Router code coverage CI check failing with:

0.94% of functions in router.py are not tested: ['_async_filter_health_check_unhealthy_deployments', '_filter_health_check_unhealthy_deployments']

Summary

Failure Path (Before Fix)

router_code_coverage.py only scans test files with "router" in the filename. The test file test_health_check_routing.py didn't match this filter, so the two functions appeared untested despite having full test coverage.

Fix

Renamed test_health_check_routing.py → test_router_health_check_routing.py so the coverage scanner picks it up.

Testing

• python3 ./tests/code_coverage_tests/router_code_coverage.py now reports untested_perc: 0.0
• All 9 tests in the renamed file pass

Type

🐛 Bug Fix
✅ Test

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Project	Deployment	Actions	Updated (UTC)
litellm	Ready	Preview, Comment	Mar 30, 2026 8:18pm

[codspeed-hq]

Merging this PR will not alter performance

✅ 16 untouched benchmarks

---

_{Comparing litellm_/objective-mendel (4f03273) with main (1757e1d)}

[greptile-apps]

Greptile Summary

This PR fixes a false-positive CI failure in the router code-coverage check by renaming test_health_check_routing.py → test_router_health_check_routing.py. The coverage scanner (router_code_coverage.py) only processes test files whose name contains the word "router" (line 45: if file.endswith(".py") and "router" in file.lower()), so the two functions _filter_health_check_unhealthy_deployments and _async_filter_health_check_unhealthy_deployments were incorrectly flagged as untested despite having full mock-based coverage. The rename is the minimal correct fix; no test logic was modified.

• Root cause identified correctly: the scanner's filename filter is well understood and the fix directly addresses it.
• Test content unchanged: 100% similarity index confirms no test weakening or regression masking.
• All 9 tests use mock objects (FakeRouter, DualCache) — no real network calls, consistent with the test isolation policy.
• Evidence of fix provided: PR description includes the expected untested_perc: 0.0 output and confirms all 9 tests pass after the rename.

Confidence Score: 5/5

• Safe to merge — pure file rename with no logic changes.
• The change is a single file rename with 100% content similarity. It correctly targets the root cause (the coverage scanner's filename filter), does not modify any test assertions, and provides evidence of resolution. No P0/P1 issues found.
• No files require special attention.

Important Files Changed

Filename	Overview
tests/test_litellm/router_utils/test_router_health_check_routing.py	Renamed from test_health_check_routing.py; file content is 100% identical — adds "router" to filename so the coverage scanner (which filters on "router" in file.lower()) picks it up correctly.

Flowchart

%%{init: {'theme': 'neutral'}}%%
flowchart TD
    A["router_code_coverage.py\nscans test directories"] --> B{"'router' in\nfilename?"}
    B -- "No ❌\ntest_health_check_routing.py\n(before rename)" --> C["Skipped\n→ functions appear untested\n→ CI fails"]
    B -- "Yes ✅\ntest_router_health_check_routing.py\n(after rename)" --> D["File processed\n→ functions marked tested\n→ CI passes"]

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_{Reviews (2): Last reviewed commit: "Merge remote-tracking branch 'origin/mai..." | Re-trigger Greptile}