# WP-71 — Test framework coherence: BDD/DDD alignment + closing the illegal-state escape hatches

Status: done (b937e55..3652ff8)
Phase: 12 — DDD hardening

## Why

WP-70 shipped test-data builders and ADR-0006, then a three-angle audit (BDD conventions,
DDD alignment, type-safety of test code) asked whether the framework as a whole is "the best
way to set up testing." It was not — and the gap was not where WP-70 looked.

**WP-70 built the door but left the walls open.** `unwrapOk` had zero call sites; `given()`
was adopted in 4 specs. Meanwhile 76 `as any` casts survived in the three biggest wizard
specs, and the reason was systemic: `eslint.config.mjs` blanket-exempted every `*.spec.ts`
from the `any` ban, and no gate anywhere ran `tsc --noEmit` over spec files, so a wrong cast
could never fail the build. One assertion
(`org-template.machine.spec.ts`, `s.tag === 'loaded' && s.dirty`) passed vacuously whenever
the tag was wrong.

Alongside that: the documented "never assert on `$localize` copy" ban was broken in 5 files;
`bdd.mdx` mis-cited its own exemplar as "one transition per test"; `layers.mdx` still taught
the pre-WP-67 six-context structure with no `apps/`+`libs/` split; backend tests were
organised by technical concern (`RuleTests.cs` held 5 aggregates as nested classes) rather
than by aggregate; and duplicated FE/BE rules (the scholing threshold, the phone-format regex)
had no test spanning the seam, so they could silently diverge.

## Read first

- `docs/reference/architecture/0006-test-data-builders.md` (WP-70's ADR).
- `libs/shared/docs/bdd.mdx`, `libs/shared/docs/layers.mdx` (both rewritten by this WP).
- `backend/tests/BigRegister.Tests/Acceptance/BesluitLifecycleTests.cs` — the canonical G/W/T
  shape both docs now point at.

## Decisions (pre-made, don't relitigate)

1. **No Gherkin/Cucumber.** Feature files bind steps by runtime string matching, which
   directly undoes the compile-time guarantees WP-70 added, and need two frameworks
   (.NET + TS) for an audience of developers, not scenario-co-authoring stakeholders. Instead:
   generate a business-readable behaviour spec FROM the test names (`gen-behaviour-spec.mjs`,
   modeled on the existing `gen-snippets.mjs`), gated for drift in CI. Test names stay the
   single source of truth.
2. **Playwright stays** — no change to the e2e framework.
3. **Given/When/Then becomes the default structure for ALL tests** (user override of the
   audit's initial recommendation). `bdd.mdx`'s old "no G/W/T ceremony" clause is removed and
   inverted; ADR-0006 already matched. Present-tense declarative naming is unchanged. The
   _retrofit_ in this WP covers the acceptance specs, the canonical exemplars, and every file
   the other tracks already opened — not a mechanical sweep of all ~600 tests (tracked as a
   follow-up).
4. **Hardening = one helper + four gates.** `expectTag(state, tag)` replaces every unsafe
   narrowing cast; the ESLint spec exemption is removed; `npm run typecheck` is added; a
   dependency-cruiser rule keeps test helpers out of production.
5. **FE/BE seam: document + one worked pattern**, not full seam coverage. `check-seam.sh`
   catches the scholing-threshold literal drift; the other three divergences (phone regex,
   disjoint eligibility fixtures, toelichting rule) are documented, not fixed. Scholing
   _enforcement_ stays WP-69's job.

## Files

| Track                    | Representative paths                                                                                                                                                                                                                                          |
| ------------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| A · hardening            | `libs/shared/src/testing/expect-tag.ts` (new); the three wizard machine specs + `*has-progress.spec.ts` + `aanvraag-view.spec.ts`; `eslint.config.mjs`, `.dependency-cruiser.base.js`, `package.json`, CI; `Builders/AanvraagBuilder.cs`, endpoint test files |
| B · BDD                  | `libs/shared/docs/bdd.mdx`, ADR-0006; the 5 copy-assertion files; the multi-behaviour title splits                                                                                                                                                            |
| C · DDD                  | `libs/shared/docs/layers.mdx`; `RuleTests.cs` → `Domain/*RuleTests.cs`; new specs for `isStatusConsistent`, `OrgTemplateRules.RejectDraft`, both apps' `session.ts`                                                                                           |
| D+E · living docs + seam | `scripts/gen-behaviour-spec.mjs`, `libs/shared/docs/behaviour-spec.mdx` (generated), `scripts/check-seam.sh`                                                                                                                                                  |

## Steps

Executed as four tracks: A/C/D+E ran file-disjoint in parallel first; B ran after, since its
doc rewrite needed to reflect what A/C actually converted. Each track ended its own layer
green; a combined gate followed; then per-track commits.

## Acceptance criteria

- [x] `expectTag` replaces all 76 `as any` + 12 `as Extract<>` state-narrowing casts across
      the three biggest wizard specs and the `*has-progress`/`besluit`/`change-request` specs.
      Zero tests legitimately started failing — every wrong-variant read the casts were hiding
      turned out to already be correct.
- [x] The vacuous assertion in `org-template.machine.spec.ts` (and, on inspection, every
      sibling instance of the same pattern in that file) is fixed.
- [x] Four new gates proven to actually fail before being trusted: `npm run lint` fails on a
      planted `any`; a deliberately-wrong `expectTag` call fails with a named
      "expected X, got Y" error, not `undefined`; `npm run dep:check` fails on a planted
      production import of `libs/shared/src/testing`; `npm run typecheck` fails on a planted
      type error in a spec.
- [x] `check-seam.sh` proven to fail when the two scholing-threshold literals are set to
      different values, with both file paths and values named in the error.
- [x] Backend test count: 220 (WP-70 baseline) → 230 (+9 `OrgTemplateRuleTests`, +1 from the
      `Unknown_id_404s_and_zorgverlener_is_forbidden` split). File count in
      `RuleTests.cs`'s place: 0 (deleted) → 7 files under `Domain/`, same total test count
      moved (plus the new file).
- [x] Frontend test count grew only from legitimate title splits (no assertion dropped) and
      the new session/isStatusConsistent specs — before/after counts reported per file by the
      owning track.
- [x] `layers.mdx` reflects the actual WP-67 monorepo structure (`apps/`+`libs/`,
      dependency-cruiser as the real enforcement mechanism, not ESLint).
- [x] `bdd.mdx`'s "one transition per test" citation of `registratie-wizard.machine.spec.ts`
      is true again (the cited test was split).
- [x] Every one of the 5 documented `$localize`-copy-assertion violations is fixed or
      explicitly justified as the doc's own escape hatch (a `reden` free-text passthrough with
      no backing tag — `aanvraag-view.spec.ts`/`beoordeling-view.spec.ts` — left alone with an
      inline comment explaining why, rather than forcing a fake enum into production code).
- [x] `npm run ci` green (lint, typecheck, dep:check, format, check:tokens, check:seam, all
      four test projects, both localized builds, audit, backend format+test, snippet drift,
      behaviour-spec drift, api-client drift). `npm run build-storybook` green (the new/edited
      MDX pages build without error).

## Verification

```bash
npm run typecheck && npm run lint && npm run dep:check && npm run check:seam
npm run ci                                                        # green (2026-08-18)
npm run build-storybook                                           # green
cd backend && dotnet test BigRegister.slnx --filter "Category!=Integration"   # 230/230
```

## Out of scope

- Universal Given/When/Then sweep across all ~600 tests (staged instead — retrofit covers the
  files this WP already touched; the rest adopt it as they're next edited).
- Scholing threshold _enforcement_ — WP-69 owns it.
- Reconciling the phone-format regex divergence in production code (documented, not fixed;
  verified not a live bug — the FE normalises `+31`→`0` before the wire).
- Making `Aanvraag` genuinely immutable (EF refactor, inherited from WP-70).
- E2E test isolation via a dev-only seed endpoint (inherited from WP-70).
- `RegistrationStatus`'s flat-record gap on the backend (inherited from WP-70).

## Risks

- `expectTag`'s runtime throw only fires when a spec actually calls it with the wrong tag —
  it does not retroactively audit every state a reducer can reach. A future variant added to
  a union still needs its own test coverage; the helper only makes existing coverage honest.
- `check-seam.sh` covers exactly one FE/BE literal pair (the scholing threshold). The other
  three documented divergences (phone regex, eligibility fixtures, toelichting) have no
  automated guard — a future edit to either side can still silently diverge undetected.