# RD-07 — Move the step-boundary decision into the 3 wizard machines

Status: done
Source: PLAN.md 1a

## Why

Each wizard component decides in the UI whether the primary button means "next step" or
"submit", duplicating a rule the reducer already owns:

| Component                            | Line    | Body                                                                             |
| ------------------------------------ | ------- | -------------------------------------------------------------------------------- |
| `herregistratie-wizard.component.ts` | 256-259 | `if (s.tag !== 'Editing') return;` then `s.step < 3 ? Next : Submit`             |
| `intake-wizard.component.ts`         | 368-371 | `if (s.tag !== 'Answering') return;` then `step() === 'review' ? Submit : Next`  |
| `registratie-wizard.component.ts`    | 613-616 | `if (s.tag !== 'Invullen') return;` then `step() === 'controle' ? Submit : Next` |

Each already-exported `next`/`submit` pair holds the real transition, so the component is
re-deriving a decision the machine can make. After this ticket, `onPrimary()` in RD-08 becomes
a single `dispatch({ tag: 'Primary' })`, and the wizard shell's `primary`/`back`/`retry`
outputs map 1:1 onto messages — which is what `.claude/skills/form-machine/SKILL.md:74-78`
already claims they do.

This ticket is **domain-only**: machines and their specs. No component changes.

## Read first

- `apps/ssp/src/app/herregistratie/domain/herregistratie.machine.ts` — `next` at 87,
  `submit` at 118, `reduce`'s `Next`/`Submit` cases at 165/171
- `apps/ssp/src/app/herregistratie/domain/intake.machine.ts` — `currentStep` at 86, `next` at
  173, `submit` at 197, cases at 226/232
- `apps/ssp/src/app/registratie/domain/registratie-wizard.machine.ts` — `currentStep` at 96,
  `next` at 265, `submit` at 284, cases at 337/343
- The three matching `*.machine.spec.ts` files
- CLAUDE.md decision 3 (state, and the naming rule for machines)

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

1. **Add `{ tag: 'Primary' }` to each of the three `Msg` unions**, plus an exported
   `primary(s)` function, plus a `case 'Primary'` in each `reduce` that delegates to it. Same
   shape as the existing `Next`/`Submit` cases.

2. **Express "last step" in each machine's own vocabulary. Do NOT invent a shared
   `isLastStep` helper.** The three state shapes genuinely differ:
   - `herregistratie`: `Editing` carries `step: 1 | 2 | 3` and there is **no `STEPS` array** →
     the test is `s.step === 3`.
   - `intake`: `Answering` carries `cursor: number` against
     `STEPS = ['buitenland','werk','review']` → the test is `currentStep(s) === 'review'`.
   - `registratie`: `Invullen` carries `cursor: number` against
     `STEPS = ['adres','beroep','controle']` → the test is `currentStep(s) === 'controle'`.

   Two of the three could share a `cursor === STEPS.length - 1` form, but the third cannot.
   A helper covering two of three, plus a special case, is more to read than three plain
   expressions.

3. **`primary` delegates to the existing exported `next` and `submit`.** Write no new
   validation and duplicate no transition logic. The whole function is a branch:

   ```ts
   export function primary(s: WizardState): WizardState {
     if (s.tag !== 'Editing') return s;
     return s.step === 3 ? submit(s) : next(s);
   }
   ```

   (…and the equivalent, in its own vocabulary, for the other two.)

4. **The guard moves into the machine.** `primary` returns `s` unchanged when the state is not
   the editing state, so RD-08 can delete the component preamble. Note the editing tag differs
   per machine: `Editing`, `Answering`, and `Invullen`. **`Invullen`/`Indienen`/`Ingediend`/
   `Mislukt` are correct Dutch domain tags per CLAUDE.md — do not "fix" them to English.**

5. **KEEP `Next` and `Submit` in all three `Msg` unions.** Verified: they are dispatched
   across **9 spec files**, including `intake.acceptance.spec.ts`, which uses them as a
   readable behaviour narrative, and the three `*-has-progress.spec.ts` files. Removing them
   would rewrite dozens of spec lines for no gain. `Primary` is purely **additive**.

6. **Do not touch any component.** RD-08 migrates the three wizards. If you edit a
   `*.component.ts` in this ticket, it is out of scope.

7. **Keep `SCHOLING_THRESHOLD_DEFAULT` greppable.** `npm run check:seam` greps for it as a
   top-level `export const` in `intake.machine.ts:43`. Do not move or inline it.

## Files

- `apps/ssp/src/app/herregistratie/domain/herregistratie.machine.ts` + `.spec.ts`
- `apps/ssp/src/app/herregistratie/domain/intake.machine.ts` + `.spec.ts`
- `apps/ssp/src/app/registratie/domain/registratie-wizard.machine.ts` + `.spec.ts`

## Steps

1. In each machine: add `{ tag: 'Primary' }` to the `Msg` union, export `primary(s)` next to
   `next`/`submit`, and add the `case 'Primary'` to `reduce`.
2. In each machine spec: add the three cases from Acceptance below.
3. Run `npm run gen:behaviour-spec` — new `it()` titles otherwise fail the drift check.
4. Update this ticket's `Status:` to `done` and the README's RD-07 row to `done`.
5. Commit all of it together.

## Acceptance criteria

Three cases per machine spec (9 total), pure `reduce` calls, no TestBed:

```
- Primary advances to the next step from a non-final step
- Primary submits from the final step
- Primary is a no-op from a non-editing state
```

The third case is what lets RD-08 delete the component guard, so do not skip it.

```bash
npm test          # exits 0
npm run ci        # exits 0
```

Prove `Primary` produces exactly what the components produce today, so the migration in RD-08
is behaviour-preserving. For each machine, these must be equal:

```
reduce(s, { tag: 'Primary' })  ===  reduce(s, { tag: 'Next' })      // at a non-final step
reduce(s, { tag: 'Primary' })  ===  reduce(s, { tag: 'Submit' })    // at the final step
```

Prove nothing was removed:

```bash
grep -c "tag: 'Next'\|tag: 'Submit'" apps/ssp/src/app/herregistratie/domain/intake.machine.ts
# Next and Submit must still be in the union and still handled in reduce
```

## Verification

`npm run ci`. This ticket touches no story, no `.mdx` and no component, so `--full` is not
required.

## Out of scope

- The three components. RD-08.
- `besluit.machine.ts` and `change-request.machine.ts` — single-step forms with no step
  boundary, so `Primary` would mean nothing there. RD-06 handles those two.
- Removing `Next`/`Submit` (decision 5).
- Renaming the Dutch tags in `registratie-wizard.machine.ts` (decision 4).

## Risks

- **`behaviour-spec.mdx` drift.** 9 new `it()` titles across 3 spec files.
  `scripts/ci-local.sh` regenerates `libs/shared/docs/behaviour-spec.mdx` from a path-sorted
  walk of spec titles and fails on any drift. Run `npm run gen:behaviour-spec` in the same
  commit.
- **`check:seam`** greps `SCHOLING_THRESHOLD_DEFAULT` (decision 7) and
  `besluit.machine.ts`'s `BESLUIT_TAGS`. Neither should move, but if `check:seam` fails, that
  is why.
- **`snippets.generated.ts` drift.** `intake.machine.ts:59` carries a
  `// #region showcase:steps` marker around `STEPS`. If your edit moves or splits that region,
  run `npm run gen:snippets` in the same commit.
- **Do not make `primary` clever.** It is a three-line branch delegating to two existing
  functions. If it grows validation, error mapping, or a cursor calculation, the transition
  logic has been duplicated instead of reused.