# X_TEST_REGISTRY_LEAK

## Means

a test file left a process-global registry dirty

## Typical cause

a `declareTags()` or `registerTier()` call with nothing to undo it, in a test body **or in the file's own `beforeAll`**. Boot calls are the file's to clean up, and a leaked one silently changes the *next* file's premise — `assertKnownTags` short-circuits while nothing is declared, so one leaking file switched tag validation on for the rest of the process and a different package's tests failed. The baseline is sampled at the end of module evaluation, not at the first `beforeEach`: a preload's `beforeEach` runs *after* the file's `beforeAll`, so sampling there counted a `beforeAll` leak as part of the baseline and reported nothing. The `cause` names every offending file and what each left behind, never the file that happened to be running when it surfaced

## Fix

the `fix` names the file and ends in a command that reproduces it — `in "<file>" add: import { isolateDeclaredTags } from '@ultimat3/cache'; const restoreTags = isolateDeclaredTags(); afterAll(restoreTags); — then re-run: bun test "<file>"` — with `const restoreTiers = isolateTiers(); afterAll(restoreTiers);` for tiers, from the same import. **Never a reset:** `resetTiers()` drops what a *neighbour* registered, and this guard reports additions only, so the damage lands as a failure in an innocent file with nothing pointing back. Entity and job registries are **not** covered — declaring at module scope is the idiom there, so a test that assumes an empty one calls `isolateEntityRegistry()` from `@ultimat3/testing/registry-isolation` (its own entry point, so the general harness does not load the entity registry) instead

[Testing](/error-codes#testing)