# RB-21 — extract the read half of `createDraftSync` into `find-concept.ts`

Status: **implemented** · 2026-08-27 · Source finding: `04-cqrs-light.md` CQ-001 ·
`00-baseline.md` §4a (`createDraftSync` 143 lines, the largest function in the repo), §9
(`fn > 40` threshold) · `99-backlog.md` RB-21

## What was wrong

`createDraftSync` (`apps/ssp/src/app/registratie/application/draft-sync.ts`) was registered
as a command factory but owned three read paths (`load`, `findConcept`, and the read half of
`resume`) mixed into the same function as the write path (`ensureId`, `flush`, `submit`,
`reset`). CQ-001 named three pieces of shared mutable closure state — `id`, `ensuring`,
`resumeGate` — as load-bearing: `resumeGate` exists only so the write path (`ensureId`) can
wait for the read path (`resume`) to finish. That coupling is genuine and stays in place.

## What changed

CQ-001's proposal, applied as a pure move, no redesign.

| File                                                                  | Change                                                                                                                                                                                                                                                                                      |
| --------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `apps/ssp/src/app/registratie/application/find-concept.ts` (new)      | `findConcept(adapter, type)` and `loadConcept(adapter, id)` — free functions taking `ApplicationsAdapter`, no `inject()`. `loadConcept` returns a `LoadedConcept` union (`{tag:'concept', draft}` \| `{tag:'not-concept'}`) instead of the boolean-shaped branching the inline version had. |
| `apps/ssp/src/app/registratie/application/find-concept.spec.ts` (new) | Direct spec, no TestBed — a fake `ApplicationsAdapter` object passed straight to the functions.                                                                                                                                                                                             |
| `apps/ssp/src/app/registratie/application/draft-sync.ts`              | Removed the inline `findConcept` closure and the body of `load`; both now call the free functions. `createDraftSync` keeps `id`, `ensuring`, `resumeGate`, and the whole write path, unchanged.                                                                                             |
| `libs/shared/docs/behaviour-spec.mdx`                                 | Regenerated (`npm run gen:behaviour-spec`) — picks up the new `find-concept.spec.ts` describe blocks.                                                                                                                                                                                       |

`createDraftSync` shrank from 187 lines (`export function createDraftSync` to its closing
brace, HEAD~1) to 169 lines. The whole file went from 236 to 216 lines.

The two call sites that used the old inline `findConcept()` now pass the adapter and type
explicitly:

```ts
// ensureId's 409-recovery catch (WP-35)
const existing = await findConcept(adapter, deps.type);
```

```ts
// resume(), no ?aanvraag in the URL
const existing = await findConcept(adapter, deps.type);
```

`load` keeps setting the closure `id` and calling `applyResume` (both closure-dependent), but
delegates the actual read to `loadConcept`:

```ts
const load = (linked: string): Promise<void> => {
  id = linked;
  return loadConcept(adapter, linked).then((result) => {
    if (result.tag === 'not-concept') {
      id = undefined;
      applyResume(null);
      return;
    }
    applyResume(result.draft);
  });
};
```

## `draft-sync.spec.ts` — unchanged

`draft-sync.spec.ts` was not edited. It never called `resume()`/`load()` directly — its
coverage is the debounce, `submit()` (including the 409-recovery path, which exercises the
extracted `findConcept` indirectly through `ensureId`'s catch), and `flushPending`. All of
that stayed in `createDraftSync`, so the spec is unchanged and still exercises the wiring
between `createDraftSync` and the two new free functions (the 409-recovery test would fail if
that wiring were wrong). It passed unchanged, 8/8.

## The new spec, and its verified red

`find-concept.spec.ts` covers the branches CQ-001 named:

- `findConcept`: match found → id returned; no match of that type → `undefined`; match found
  but not `Concept` status → `undefined`; `adapter.list()` resolves to an unparsable shape
  (`parseApplications` fails) → `undefined`; `adapter.list()` rejects → `undefined`.
- `loadConcept`: `Concept` with a draft → `{tag:'concept', draft}`; `Concept` with no draft →
  `{tag:'concept', draft:null}`; a non-`Concept` status (e.g. `Ingediend`, submitted) →
  `{tag:'not-concept'}`; `adapter.detail()` rejects (unknown/deleted id) →
  `{tag:'not-concept'}`.

**Verified red without the fix.** Used `Edit` (not `git checkout`) to invert one condition in
`loadConcept` — `dto.status.tag !== 'Concept'` → `dto.status.tag === 'Concept'` — reran `ng
test ssp --include find-concept.spec.ts`. Result: 3 of 9 tests failed —

```
loadConcept > reads the draft off a Concept
  AssertionError: expected { tag: 'not-concept' } to deeply equal { tag: 'concept', draft: { step: 1 } }
loadConcept > reports a missing draft as null
  AssertionError: expected { tag: 'not-concept' } to deeply equal { tag: 'concept', draft: null }
loadConcept > reports not-concept when the id has moved past Concept (submitted)
  AssertionError: expected { tag: 'concept', draft: null } to deeply equal { tag: 'not-concept' }
```

Then used `Edit` again to flip the condition back to `!==`, reran the same command: 9/9
green. `findConcept`'s and `loadConcept`'s other branches were not separately mutated — the
inverted condition alone was enough to prove the spec is sensitive to the extraction being
correct, and re-verifying full green after the revert confirmed no collateral change was left
in the file.

## Scope held

- No restructuring of the write path (`ensureId`, `flush`, `submit`, `reset`) — untouched
  beyond the two call-site updates shown above.
- `applications.adapter.ts` was not split (CQ-002's "Not filed" note rules that out for this
  design; out of scope here regardless).
- `resume()`'s semantics (URL-param precedence, the `resumeGate` release-in-`finally`, the
  navigate-to-stamp-the-id side effect) are unchanged — only its two `findConcept()`/`load()`
  calls now go through the free functions.
- No wire change, no DTO change, no behaviour change.

## Verification

`npm run ci` (foreground): **green** — lint, typecheck, `dep:check`, `format:check`,
`check:tokens`, `check:seam`, tests (ssp includes `find-concept.spec.ts` 9/9 new,
`draft-sync.spec.ts` 8/8 unchanged), `ng build --localize` (both apps), `npm audit`, backend
`dotnet test` (the known `OpenZaakIntegrationTests.Admin_cases_…` container-dependent failure
is expected and outside `npm run ci`'s scope), `gen:snippets` drift clean, `gen:behaviour-spec`
drift clean once the regenerated file is committed alongside the code. Full counts are in the
commit's `npm run ci` run — see the session note for the exact step-by-step output.