docs(website): add Discord bot test plan

Document the test plan for the bot/ workspace — the last of the three website
npm workspaces without a suite (server + client landed in website PR #86).
Records the shared node --test conventions (no jest/vitest/jsdom; DB pool at a
dead port; Discord objects hand-faked) and maps the meaningful bot behavior to
lock: the normalize/duration/spam pure logic, the invite/site-api/internal-key
single-collaborator units, the messageFilter pipeline (bypass-first decision
order + fixed-duration mute + best-effort recording), and the models with real
shaping logic. Includes the CI + SonarQube coverage wiring to mirror PR #86 and
a suggested phasing.

Co-Authored-By: Claude <noreply@anthropic.com>

website/test-plan.md

@@ -0,0 +1,154 @@
+# Runic Gateway Website — Test Plan (Discord bot)
+
+> Companion to [website-README.md](website-README.md) (overview) and
+> [BACKEND_DESIGN.md](BACKEND_DESIGN.md) (server API/schema/security contract).
+> Establishes the test plan for the **`bot/` workspace** (the Discord bot), the
+> last of the three `website` npm workspaces without a suite. The server and
+> client suites already exist (website PR #86); this doc closes the bot gap and
+> records the shared conventions so all three stay consistent.
+
+## 1. Goal & philosophy
+
+Cover **meaningful bot behavior** — the moderation/filter decisions a future
+change could silently break — not a coverage number. The bot's value is in *what
+it decides to delete, warn, mute, or let through*; a good test reads "given this
+message + config, what action does the bot take?", never "did this function call
+that function?".
+
+The whole `website` repo tests on **Node's built-in runner (`node --test`)** with
+**zero external test dependencies** — no jest, no vitest, no jsdom. Unit tests
+run without a database or a live Discord gateway: the DB pool is pointed at a dead
+port and every collaborator (`db.query`, a model, a Discord `message`/`client`) is
+replaced with an in-memory fake. This mirrors the server suite exactly (the bot is
+CommonJS, like the server — `require`/`module.exports` — so the same patterns
+apply verbatim).
+
+## 2. Current state
+
+| Workspace | Runner | Status |
+|---|---|---|
+| `server/` | `node --test` | **Exists** — models, controllers, auth/session, shard ingest. |
+| `client/` | `node --test` (pure-logic ESM) | **Exists** (PR #86) — `lib/`, `api/`, `data/`. |
+| `bot/` | — | **This plan** — no runner or tests yet. |
+
+The 46% SonarQube aggregate is dragged down by the bot (and the client's
+un-unit-testable React components) reading as 0% covered. Standing up the bot
+suite lifts the real number and, more importantly, locks the filter/moderation
+rules.
+
+## 3. Harness
+
+Add a test script to `bot/package.json` (mirrors server/client):
+
+```json
+"scripts": { "test": "node --test" }
+```
+
+Conventions, identical to `server/test/`:
+
+- **No DB.** Set `process.env.DB_HOST = '127.0.0.1'` / `DB_PORT = '59999'` at the
+  top of any test whose module transitively `require`s `../db`, so the pool is
+  built against a dead port and a stray query fails fast instead of hanging.
+  Models are exercised by monkeypatching `db.query` (or the model method the unit
+  under test calls) with an in-memory fake; restore it in `afterEach`.
+- **No Discord.** The `discord.js` `Client`, `Message`, `GuildMember`, and
+  `Interaction` objects are hand-rolled fakes carrying only the fields the unit
+  reads (e.g. `message.mentions.users.size`, `message.member.roles.cache`,
+  `message.client.fetchInvite`). Never construct a real client or open a gateway
+  connection.
+- **Tests live in `bot/test/*.test.js`.** One file per module under test.
+
+## 4. Units to cover
+
+Ordered high-value first. Each row names the module, the behavior worth locking,
+and the seam a test drives it through.
+
+### 4.1 Pure logic (no mocks beyond inputs)
+
+| Module | Behaviors to lock | Notes |
+|---|---|---|
+| `filter/normalize.js` | leetspeak folding (`b4d`→`bad`, `@ss`→`ass`), 3+-repeat collapse (`sooooo`→`so`), case-fold; `matches()` is word-boundary anchored (so `bad` does not fire inside `badminton`); `findMatch()` returns the first `{word, severity}` row or `null`; the *documented gaps* stay gaps (spaced-out `b a d` is **not** caught). | The core obfuscation-resistance contract. Pin the gaps too, so a future tightening is a deliberate, test-visible change. |
+| `utils/duration.js` | `"30s"/"10m"/"2h"/"1d"` → correct ms; whitespace tolerated; garbage/empty/unknown-unit → `null`; `MAX_TIMEOUT_MS` is 28 days (the Discord cap callers clamp to). | Feeds `/mute` and temp-role expiry — a wrong parse mutes for the wrong span. |
+| `filter/spamFilter.js` | `isRateLimited` trips on the 6th message inside the 5 s window and is per-`guild:user`; it has a **side effect** (records the timestamp) so it must be called once; `isMassMention` counts users **+** roles against the threshold; `isMassEmoji` counts custom `<:name:id>` and unicode pictographs. | Drive time with a stubbed `Date.now` (or accept the real clock and use tight windows). The module-load `setInterval(...).unref()` sweep must not keep the runner alive — `.unref()` already handles this; assert no leak by letting the suite exit. |
+
+### 4.2 Logic with a single mocked collaborator
+
+| Module | Behaviors to lock | Seam / mock |
+|---|---|---|
+| `filter/inviteFilter.js` | returns the **code** (not a bool) of the first *foreign* invite; an invite resolving to the current guild is allowed; an invite that **fails to resolve** (expired/invalid) is treated as foreign (fail-closed); no invite in the message → `null`. | Fake `message.client.fetchInvite(code)` — resolve with `{ guild: { id } }` for local/foreign, or throw for unresolvable. Set `message.guildId` + `message.content`. |
+| `site/siteApiClient.js` | never throws on a network/timeout/HTTP failure — always returns the `{ ok, ... }` shape so a command never breaks when the site is down: `{ ok: true, data }` on success, `{ ok: false, error }` on failure, and the distinct `{ ok: false, maintenance: true, message }` for the site's 503 maintenance response. (Public read client — **no** shared secret; the keyed channel is `botInternalClient.js`.) | Stub `global.fetch` (resolve various statuses/bodies, reject/timeout via `AbortController`). Same non-throwing contract the server's `uoLinkClient` follows. |
+| `internal/requireInternalKey.js` | `401` on a missing/wrong key; `next()` on the configured key; **fail-closed** when `BOT_INTERNAL_KEY` is empty (never matches); timing-safe compare (equal-length + `crypto.timingSafeEqual`, no early-exit length leak). | Call the middleware with a fake `req` (`req.get('X-Internal-Key')`) + `res`/`next` spies; mirrors `server/test/requireInternalKey.test.js`. |
+
+### 4.3 The filter pipeline (orchestration)
+
+`discord/messageFilter.js` is the highest-value integration seam — it composes
+all of §4.1–4.2. Lock the **decision order and the actions**, with every
+collaborator faked:
+
+- **Bypass wins first:** an allow-listed channel, or a member holding an
+  allow-listed role, short-circuits the whole pipeline (`isBypassed`) — no
+  delete, no hit recorded.
+- **Order:** invite link → banned word → spam (rate-limit → mass-mention →
+  mass-emoji). `detectSpam` must evaluate `isRateLimited` **first and exactly
+  once** (it has the timestamp side effect).
+- **Actions:** invite/spam always delete + warn (no severity tiers); a
+  word-filter hit applies the action for its severity; filter-triggered mutes use
+  the fixed `FILTER_MUTE_SECONDS` (600 s).
+- **Best-effort recording never breaks moderation:** `recordFilterHit` /
+  `recordSpamHit` throwing must be swallowed — the delete/warn still happens.
+
+Mocks: `filterCache` (in-memory `allowChannels`/`allowRoles` Sets + words), a fake
+`message` (content, author, member roles, `delete()`, `guildId`), and spies on
+`warnings`/`filterHits`/`spamHits`/`modLog` to assert what was called.
+
+### 4.4 Models (`bot/model/*.js`)
+
+Thin `db.query` wrappers (e.g. `warnings.js`, `filterWords.js`, `filterHits.js`,
+`spamHits.js`, `memberEvents.js`, `guildConfig.js`, `scheduledMessages.js`,
+`tempRoles.js`). Cover only those with **shaping/branching logic** (a query that
+maps rows, applies an "active/not-expired" predicate, or upserts) by asserting the
+**SQL params** passed to a fake `db.query` and the shape returned. Skip pure
+one-line inserts with no logic — testing those only proves the mock.
+
+## 5. Explicitly out of scope
+
+- **`discord.js` internals / the live gateway** — not ours to test; never open a
+  real connection.
+- **Thin command wrappers** (`discord/commands/*.command.js`) that only validate
+  args and call a Discord API + a model — cover their *logic* (arg parsing,
+  duration clamping) if any, but not the Discord round-trip.
+- **`node-cron` scheduling itself** — test the job's callback logic, not that cron
+  fires.
+
+## 6. CI & coverage wiring
+
+Mirror what PR #86 did for the client:
+
+- **`.gitea/workflows/pr-checks.yml`** — add a `bot-tests` job (or a
+  `Run bot tests` step) that runs `npm test --prefix bot`, gating PRs into `main`.
+- **`.gitea/workflows/sonarqube.yml`** — generate a bot LCOV from the repo root so
+  `SF:` paths resolve to `bot/src/...`:
+
+  ```
+  node --test --experimental-test-coverage \
+    --test-reporter=lcov --test-reporter-destination=bot/coverage/lcov.info \
+    bot/test/*.test.js
+  ```
+
+- **`sonar-project.properties`** — add `bot/test` to `sonar.tests`, the glob to
+  `sonar.test.inclusions`, `bot/coverage/lcov.info` to
+  `sonar.javascript.lcov.reportPaths`, and `bot/coverage/**` to `sonar.exclusions`.
+  (`bot/src` is already in `sonar.sources`.)
+
+Bot units need no `npm ci` to run when they import only relative files + Node
+built-ins; a test that stubs `global.fetch` or fakes `db` needs no `discord.js`
+either. Keep the pool pointed at a dead port so the run is hermetic.
+
+## 7. Suggested phasing
+
+1. **Harness + pure logic** — `test` script, then `normalize`, `duration`,
+   `spamFilter`. Fast, zero mocks, immediate value.
+2. **Single-collaborator units** — `inviteFilter`, `siteApiClient`,
+   `requireInternalKey`.
+3. **Pipeline** — `messageFilter` decision order + actions (the payoff test).
+4. **Models with logic**, then the **CI/Sonar wiring** so it all counts.