[chat] updates to privacy and filters

apps/api/package.json

@@ -16,6 +16,7 @@
 		"test": "run-vitest"
 	},
 	"dependencies": {
+		"@2toad/profanity": "3.3.0",
 		"@repo/domain": "workspace:*",
 		"@repo/hono-helpers": "workspace:*",
 		"@repo/jwt": "workspace:*",

apps/api/src/openapi.ts

@@ -556,7 +556,7 @@ export const SuccessValueEnvelope = z.object({ success: z.boolean(), value: z.nu
 /** `POST /api/sanitize/v1` JSON body — the text to clean. */
 export const SanitizeRequest = z.object({ Value: z.string() })
 
-/** `POST /api/sanitize/v1/isPure` — whether the text is clean (always true here). */
+/** `POST /api/sanitize/v1/isPure` — whether the text is free of profanity. */
 export const IsPureResponse = z.object({ IsPure: z.boolean() })
 
 /** `GET /api/keepsakes/globalconfig` — the keepsake feature switches. */

apps/api/src/routes/gameplay.ts

@@ -3,7 +3,9 @@ import { describeRoute } from 'hono-openapi'
 
 import charadesWords from '../../static/charades.json'
 import communityBoard from '../../static/community-board.json'
+import { authedId, unauthorized } from '../http'
 import {
+	AUTHED,
 	BareString,
 	idParam,
 	IsPureResponse,
@@ -15,10 +17,23 @@ import {
 	KeepsakeConfig,
 	SanitizeRequest,
 	stringParam,
+	UNAUTHORIZED_RESPONSE,
 } from '../openapi'
+import { containsSwears } from '../sanitize'
 
+import type { Context } from 'hono'
 import type { App } from '../context'
 
+/**
+ * The text to check, from the JSON body the client posts (`{ "Value": "..." }`). A body
+ * that isn't JSON, or carries no `Value`, reads as the empty string — which every caller
+ * here treats as "nothing to object to" rather than as a bad request.
+ */
+async function sanitizeValue(c: Context<App>): Promise<string> {
+	const body = await c.req.json<{ Value?: unknown }>().catch(() => ({}) as { Value?: unknown })
+	return typeof body.Value === 'string' ? body.Value : ''
+}
+
 // Text sanitization, keepsakes, objectives/events/rewards, and the misc analytics
 // sinks the client hits during load.
 export const gameplayRoutes = new Hono<App>({ strict: false })
@@ -36,21 +51,34 @@ export const gameplayRoutes = new Hono<App>({ strict: false })
 			requestBody: jsonBody(SanitizeRequest, 'The text to clean'),
 			responses: { 200: json(BareString, 'The input text, unchanged (a bare JSON string)') },
 		}),
-		async (c) => {
-			const body = await c.req.json<{ Value?: unknown }>().catch(() => ({}) as { Value?: unknown })
-			return c.json(typeof body.Value === 'string' ? body.Value : '')
-		}
+		async (c) => c.json(await sanitizeValue(c))
 	)
+	// The yes/no form of the filter, and the one that actually filters: the client asks
+	// this before it accepts a display name, a room name or an invention title. Auth-gated,
+	// as the reference is — the client only ever asks while logged in.
 	.post(
 		'/api/sanitize/v1/isPure',
 		describeRoute({
 			tags: ['Gameplay'],
 			summary: 'Whether a string is clean',
-			description: 'The yes/no form of the filter. Always `true` — nothing is filtered here.',
+			description:
+				'Reports whether the posted `Value` contains a swear — the check the client runs ' +
+				'against a display name, room name or invention title before it accepts one. ' +
+				'Matching is word-boundary aware, so ordinary words that contain a swear ' +
+				'(`analysis`, `Scunthorpe`, `class`) are pure, while leetspeak (`sh1t`, `a$$hole`) ' +
+				'is not. An empty or absent `Value` is pure.',
+			security: AUTHED,
 			requestBody: jsonBody(SanitizeRequest, 'The text to check'),
-			responses: { 200: json(IsPureResponse, 'Always pure') },
+			responses: {
+				200: json(IsPureResponse, 'Whether the text is clean'),
+				401: UNAUTHORIZED_RESPONSE,
+			},
 		}),
-		(c) => c.json({ IsPure: true })
+		async (c) => {
+			const id = await authedId(c)
+			if (id === null) return unauthorized(c)
+			return c.json({ IsPure: !containsSwears(await sanitizeValue(c)) })
+		}
 	)
 
 	// ---- Activities -----------------------------------------------------------

apps/api/src/sanitize.ts

@@ -0,0 +1,49 @@
+import { Profanity } from '@2toad/profanity'
+
+/**
+ * The profanity filter behind `POST /api/sanitize/v1/isPure`.
+ *
+ * The word list is `@2toad/profanity`'s rather than one of ours: the hard part of this is
+ * not naming swears, it's not flagging ordinary text — a filter that rejects "Grape
+ * Escape" or "Title Screen" as a room name is worse than no filter, because the player is
+ * told their name is unacceptable and can't see why. It matches whole words, so `grape`,
+ * `analysis`, `assassin`, `class` and `Scunthorpe` come out clean, while leetspeak
+ * (`sh1t`, `a$$hole`) and letters spaced apart (`f u c k`) do not.
+ *
+ * Two knobs below adjust the list for this server; the matching itself is the library's.
+ */
+
+/**
+ * Words to filter on top of the library's list — the ones it doesn't carry but a room
+ * full of players will find. Matched as whole words like everything else, so `kys` here
+ * doesn't flag `skyscraper`.
+ */
+const EXTRA_WORDS: string[] = ['kys', 'molest']
+
+/**
+ * Innocent words that the list reads a swear inside of. Empty today — the whole-word
+ * matching means the usual victims (`shiitake`, `Scunthorpe`, `analysis`) already pass —
+ * and this is where one goes if a player ever turns up with a name it gets wrong, rather
+ * than a change to how matching works.
+ */
+const ALLOWED_WORDS: string[] = []
+
+/**
+ * Built once per isolate, not per request: the constructor compiles the word list into a
+ * regex, which is the whole reason a check costs microseconds at request time. Module
+ * scope is where that cost belongs.
+ */
+const filter = new Profanity({ wholeWord: true })
+filter.addWords(EXTRA_WORDS)
+filter.whitelist.addWords(ALLOWED_WORDS)
+
+/**
+ * Whether `value` contains a swear. Mirrors the reference server's
+ * `Sanitize.ContainsSwears`, which is the whole of what `isPure` reports.
+ *
+ * An empty value is clean — the client checks a field as it's being typed, and an empty
+ * box is not something to refuse.
+ */
+export function containsSwears(value: string): boolean {
+	return value !== '' && filter.exists(value)
+}

apps/api/src/test/integration/api.test.ts

@@ -1700,7 +1700,7 @@ describe('public endpoints', () => {
 		expect(await ids(featuredPage)).toEqual([202])
 	})
 
-	test('POST /api/sanitize/v1 echoes the value; isPure reports true', async () => {
+	test('POST /api/sanitize/v1 echoes the value', async () => {
 		const san = await exports.default.fetch(`${ORIGIN}/api/sanitize/v1`, {
 			method: 'POST',
 			headers: { 'Content-Type': 'application/json' },
@@ -1708,10 +1708,65 @@ describe('public endpoints', () => {
 		})
 		expect(san.status).toBe(200)
 		expect(await san.json()).toBe('hello world')
+	})
 
-		const pure = await exports.default.fetch(`${ORIGIN}/api/sanitize/v1/isPure`, { method: 'POST' })
-		expect(pure.status).toBe(200)
-		expect(await pure.json()).toEqual({ IsPure: true })
+	describe('POST /api/sanitize/v1/isPure', () => {
+		const isPure = async (Value?: string, authed = true) =>
+			exports.default.fetch(`${ORIGIN}/api/sanitize/v1/isPure`, {
+				method: 'POST',
+				headers: {
+					'Content-Type': 'application/json',
+					...(authed ? await bearer('42') : {}),
+				},
+				body: Value === undefined ? undefined : JSON.stringify({ Value }),
+			})
+
+		test('401s without a token', async () => {
+			expect((await isPure('hello', false)).status).toBe(401)
+		})
+
+		test.each([
+			'hello world',
+			'My Cool Room',
+			// The words a substring filter gets wrong. Rejecting these is worse than
+			// missing a swear: the player is told the name is unacceptable and can't
+			// see why.
+			'Grape Escape',
+			'Title Screen',
+			'assassin',
+			'Bass Pro Shop',
+			'analysis of the class',
+			'Scunthorpe United',
+			'shiitake mushrooms',
+			// Nothing to object to in an empty box — the client checks as you type.
+			'',
+		])('%j is pure', async (value) => {
+			const res = await isPure(value)
+			expect(res.status).toBe(200)
+			expect(await res.json()).toEqual({ IsPure: true })
+		})
+
+		test.each([
+			'fuck this',
+			// Leetspeak and symbol substitution are folded back to letters.
+			'sh1t',
+			'a$$hole',
+			'n1gger',
+			// A swear anywhere in the string, not just on its own.
+			'my totally fucking cool room',
+			// Ours, on top of the dataset — see EXTRA_PATTERNS.
+			'kys',
+		])('%j is not pure', async (value) => {
+			const res = await isPure(value)
+			expect(res.status).toBe(200)
+			expect(await res.json()).toEqual({ IsPure: false })
+		})
+
+		test('a body with no Value is pure rather than a bad request', async () => {
+			const res = await isPure()
+			expect(res.status).toBe(200)
+			expect(await res.json()).toEqual({ IsPure: true })
+		})
 	})
 })