The test-only verdict

Some code is referenced only by your tests. It’s reachable — the tests use it — but no production path leads to it. Pure-static tools call it alive (tests reference it) and miss that it’s production-dead. Necro gives it its own verdict: test-only.

testUtil  src/util.ts:4   tier: maybe
  ✓ 0 production references
  ✗ referenced only in test files
  • coverage: not available
  → prod-dead — delete fn + test, or wire into prod

How Necro decides

Necro tracks the kind of every reference edge — prod or test — based on whether the referencing file is a test file (resolved from your real test-runner config). It then runs reachability in two colors:

From production entries over prod edges → reached-by-prod (alive).
From test entries over prod + test edges → reached-by-any.

A symbol in reached-by-any but not reached-by-prod is test-only. See Dead code & reachability for the full model.

What to do about it

test-only is a signal, not a command. The fix depends on intent:

The util is genuinely unused in production → delete the function and its test.
It should be used in production → wire it in.