# RD-02 — `max-lines` guard with a self-cleaning exemption list

Status: done
Source: PLAN.md section 3a

## Why

The dashboard refactor proved a page can be 42 lines. Nothing stops the next one being 340
again, and nothing stops this arc itself adding a new oversized file. The guard therefore
lands **before** the work it protects, not after.

Seven files exceed the budget today. Each becomes a visible, dated to-do rather than a
silent one.

## Read first

- `eslint.config.mjs` — a flat array of 4 config objects. You add a 5th.
- `docs/project/readable-codebase/README.md` — the session protocol and GREEN.
- CLAUDE.md, "Enforced, not just hoped-for".

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

1. **The rule.** `max-lines` at 250, `skipBlankLines: true`, `skipComments: true`, scoped to
   `['{apps,libs}/**/*.{page,component,section,step}.ts']`.

2. **The glob must include `section` and `step`.** `*.{page,component}.ts` does **not** match
   `*.section.ts` — the file kind the dashboard refactor invented, and the kind RD-22 through
   RD-26 create most of. Omitting them lets every new file this arc produces escape the guard.
   This is the single most important line of the ticket.

3. **Add `linterOptions: { reportUnusedDisableDirectives: 'error' }`, in this same commit.**
   ESLint 9 only _warns_ by default, and `npm run lint` does not fail on warnings. At `error`,
   a disable that is no longer needed becomes a lint failure — so **every later split commit
   is forced to delete its own exemption or go red.** The exemption list cannot rot into
   permanent debt. Verified clean on the current tree, so it lands green.

4. **250 is chosen because the dashboard proves it is reachable**, not from a style guide.

5. **Seven files, not eight or nine.** The original plan counted with `wc -l`; this rule
   counts without blank lines or comments. `behandel-scherm.component.ts` (232) and
   `stamdata-table-editor.component.ts` (236) were on the old list and **already pass** —
   leave them alone.

6. **Each disable names its reason and the ticket that removes it**, per CLAUDE.md's standing
   rule. Use the exact mapping in Files below. Note `letter-canvas` is the one file whose
   disable is **expected to stay** — RD-26 rewrites its reason rather than deleting it,
   because 77 of its lines are CSS and the rest is one letter (PLAN.md 3d).

## Files

Add the config block to `eslint.config.mjs`, then a `/* eslint-disable max-lines */` header
with a one-line reason to each of these seven. Verified counts under the rule:

| Rule lines | File                                                                                          | Removed by              |
| ---------- | --------------------------------------------------------------------------------------------- | ----------------------- |
| 574        | `apps/ssp/src/app/registratie/ui/registratie-wizard/registratie-wizard.component.ts`          | RD-23                   |
| 472        | `apps/ssp/src/app/showcase/concepts.page.ts`                                                  | RD-24                   |
| 414        | `apps/ssp/src/app/brief/ui/letter-canvas/letter-canvas.component.ts`                          | RD-26 (rewrites, keeps) |
| 368        | `apps/ssp/src/app/herregistratie/ui/intake-wizard/intake-wizard.component.ts`                 | RD-22                   |
| 329        | `apps/ssp/src/app/brief/ui/org-template-editor/org-template-editor.component.ts`              | RD-25                   |
| 253        | `libs/shared/src/ui/rich-text-editor/rich-text-editor.component.ts`                           | RD-21                   |
| 252        | `apps/ssp/src/app/herregistratie/ui/herregistratie-wizard/herregistratie-wizard.component.ts` | RD-20                   |

## Steps

1. Add the 5th config object to `eslint.config.mjs` with the rule from decision 1, and a
   short comment saying why 250 and that the exemptions are the to-do list.
2. Add `linterOptions: { reportUnusedDisableDirectives: 'error' }` so it applies repo-wide.
3. Add the seven disable headers, each of the form
   `/* eslint-disable max-lines */ // <why> — removed by RD-NN`.
4. Update this ticket's `Status:` to `done` and the README's RD-02 row to `done`.
5. Commit all of it together.

## Acceptance criteria

Commands, not judgements:

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

Then prove the guard actually bites, and that the glob covers section files:

```bash
# 1. A new oversized section file must FAIL. Expect a max-lines error, then delete the file.
printf '/* x */\nexport class X {\n%s\n}\n' "$(for i in $(seq 260); do echo "  p$i = $i;"; done)" \
  > apps/ssp/src/app/registratie/ui/dashboard/tmp-probe.section.ts
npx eslint apps/ssp/src/app/registratie/ui/dashboard/tmp-probe.section.ts   # must report max-lines
rm apps/ssp/src/app/registratie/ui/dashboard/tmp-probe.section.ts

# 2. Removing any one disable must FAIL (proves all 7 are load-bearing, none is decoration).
```

## Verification

`npm run ci`. This ticket touches no story, no `.mdx` and no `libs/shared/src/ui/**`
_content_, so `--full` is not required — but `rich-text-editor.component.ts` does live under
`libs/shared/src/ui/`, and adding a comment line to it is harmless. Skip `--full`.

## Out of scope

- Splitting any of the seven files. That is RD-20 through RD-26.
- `behandel-scherm.component.ts` and `stamdata-table-editor.component.ts` — already compliant.
- The 7 non-component files over 250 lines (`brief.adapter.ts` 408, `upload.machine.spec.ts`
  364, `brief.store.spec.ts` 357, `registratie-wizard.machine.spec.ts` 287,
  `registratie-wizard.machine.ts` 285, `upload.machine.ts` 256). The glob deliberately does
  not reach specs, adapters or machines — this budget is about components.

## Risks

- **The inline-template processor can make `max-lines` fire twice per file** (once for the
  `.ts`, once for the extracted virtual `.html`). Measured: it does **not** with this glob,
  because the virtual path ends in `.html` and the glob ends in `.ts`. If a doubled report
  appears, the glob is wrong — do not "fix" it by raising the limit.
- **`reportUnusedDisableDirectives` is repo-wide**, so it also polices the generated
  `api-client.ts` header. That file is already in `ignores`, so it is out of reach. Confirmed
  clean before this change.