# `docs/testing/` — testing operations & failure-mode playbooks

> **Charter (DOC-03):** operational, task-shaped docs for *running and
> diagnosing* mgf-common's own test suite — the federation test
> supervisor's failure-mode recipes in particular. This is distinct from
> `mgf-fed standards TESTING` (the cross-project *rules*) and from
> `docs/recipes/testing.md` (the *how-to* for consumers wiring the
> fixtures). When the question is "a test went red / hung — now what?",
> the answer lives here.

## What goes here

- Failure-mode playbooks: how to read a TS-27 failure bundle, diagnose a
  hung test, interpret a supervisor crash record.
- mgf-common-specific testing operations that aren't a reusable consumer
  recipe and aren't a standards rule.

## What does NOT go here

- Cross-project testing **rules** → `mgf-fed standards TESTING`.
- Consumer **how-to** (wiring fixtures, `perf_span`, tiers) →
  `docs/recipes/testing.md`.
- Per-run artifacts (`.gates/last-run/...`) — those are generated, not docs.

## Index

| File | What it covers |
|---|---|
| [`DIAGNOSING_HANGS.md`](DIAGNOSING_HANGS.md) | The playbook a triager opens when a test hangs/crashes — failure-mode recipes referenced from the TS-27 detail bundle's "next steps" pointer. |
