fix(backend): reject unknown fields in source config

Add "+": "reject" to all arktype schemas so undeclared
keys return 400. Sources without a configSchema now
reject the config field entirely at the HTTP layer.

Co-authored-by: Ona <no-reply@ona.com>

apps/aelis-backend/src/session/user-session-manager.ts

@@ -5,10 +5,10 @@ import merge from "lodash.merge"
 
 import type { Database } from "../db/index.ts"
 import type { FeedEnhancer } from "../enhancement/enhance-feed.ts"
-import { InvalidSourceConfigError, SourceNotFoundError } from "../sources/errors.ts"
-import { sources } from "../sources/user-sources.ts"
 import type { FeedSourceProvider } from "./feed-source-provider.ts"
 
+import { InvalidSourceConfigError, SourceNotFoundError } from "../sources/errors.ts"
+import { sources } from "../sources/user-sources.ts"
 import { UserSession } from "./user-session.ts"
 
 export interface UserSessionManagerConfig {
@@ -104,16 +104,14 @@ export class UserSessionManager {
 		// read stale config. Use SELECT FOR UPDATE or atomic jsonb merge if
 		// this becomes a problem.
 		let mergedConfig: Record<string, unknown> | undefined
-		if (update.config !== undefined) {
+		if (update.config !== undefined && provider.configSchema) {
 			const existing = await sources(this.db, userId).find(sourceId)
 			const existingConfig = (existing?.config ?? {}) as Record<string, unknown>
 			mergedConfig = merge({}, existingConfig, update.config)
 
-			if (provider.configSchema) {
-				const validated = provider.configSchema(mergedConfig)
-				if (validated instanceof type.errors) {
-					throw new InvalidSourceConfigError(sourceId, validated.summary)
-				}
+			const validated = provider.configSchema(mergedConfig)
+			if (validated instanceof type.errors) {
+				throw new InvalidSourceConfigError(sourceId, validated.summary)
 			}
 		}
 
@@ -148,23 +146,24 @@ export class UserSessionManager {
 	async upsertSourceConfig(
 		userId: string,
 		sourceId: string,
-		data: { enabled: boolean; config: unknown },
+		data: { enabled: boolean; config?: unknown },
 	): Promise<void> {
 		const provider = this.providers.get(sourceId)
 		if (!provider) {
 			throw new SourceNotFoundError(sourceId, userId)
 		}
 
-		if (provider.configSchema) {
+		if (provider.configSchema && data.config !== undefined) {
 			const validated = provider.configSchema(data.config)
 			if (validated instanceof type.errors) {
 				throw new InvalidSourceConfigError(sourceId, validated.summary)
 			}
 		}
 
+		const config = data.config ?? {}
 		await sources(this.db, userId).upsertConfig(sourceId, {
 			enabled: data.enabled,
-			config: data.config,
+			config,
 		})
 
 		const session = this.sessions.get(userId)
@@ -172,7 +171,7 @@ export class UserSessionManager {
 			if (!data.enabled) {
 				session.removeSource(sourceId)
 			} else {
-				const source = await provider.feedSourceForUser(userId, data.config)
+				const source = await provider.feedSourceForUser(userId, config)
 				if (session.hasSource(sourceId)) {
 					session.replaceSource(sourceId, source)
 				} else {

apps/aelis-backend/src/sources/http.test.ts

@@ -217,6 +217,31 @@ describe("PATCH /api/sources/:sourceId", () => {
 		expect(body.error).toContain("Invalid JSON")
 	})
 
+	test("returns 400 when request body contains unknown fields", async () => {
+		activeStore = createInMemoryStore()
+		activeStore.seed(MOCK_USER_ID, "aelis.weather")
+		const { app } = createApp([createStubProvider("aelis.weather", weatherConfig)], MOCK_USER_ID)
+
+		const res = await patch(app, "aelis.weather", {
+			enabled: true,
+			unknownField: "hello",
+		})
+
+		expect(res.status).toBe(400)
+	})
+
+	test("returns 400 when weather config contains unknown fields", async () => {
+		activeStore = createInMemoryStore()
+		activeStore.seed(MOCK_USER_ID, "aelis.weather")
+		const { app } = createApp([createStubProvider("aelis.weather", weatherConfig)], MOCK_USER_ID)
+
+		const res = await patch(app, "aelis.weather", {
+			config: { units: "metric", unknownField: "hello" },
+		})
+
+		expect(res.status).toBe(400)
+	})
+
 	test("returns 400 when weather config fails validation", async () => {
 		activeStore = createInMemoryStore()
 		activeStore.seed(MOCK_USER_ID, "aelis.weather")
@@ -340,7 +365,7 @@ describe("PATCH /api/sources/:sourceId", () => {
 		removeSpy.mockRestore()
 	})
 
-	test("accepts location source with arbitrary config (no schema)", async () => {
+	test("returns 400 when config is provided for source without schema", async () => {
 		activeStore = createInMemoryStore()
 		activeStore.seed(MOCK_USER_ID, "aelis.location")
 		const { app } = createApp([createStubProvider("aelis.location")], MOCK_USER_ID)
@@ -349,7 +374,19 @@ describe("PATCH /api/sources/:sourceId", () => {
 			config: { something: "value" },
 		})
 
-		expect(res.status).toBe(204)
+		expect(res.status).toBe(400)
+	})
+
+	test("returns 400 when empty config is provided for source without schema", async () => {
+		activeStore = createInMemoryStore()
+		activeStore.seed(MOCK_USER_ID, "aelis.location")
+		const { app } = createApp([createStubProvider("aelis.location")], MOCK_USER_ID)
+
+		const res = await patch(app, "aelis.location", {
+			config: {},
+		})
+
+		expect(res.status).toBe(400)
 	})
 
 	test("updates enabled on location source", async () => {
@@ -423,6 +460,31 @@ describe("PUT /api/sources/:sourceId", () => {
 		expect(res.status).toBe(400)
 	})
 
+	test("returns 400 when request body contains unknown fields", async () => {
+		activeStore = createInMemoryStore()
+		const { app } = createApp([createStubProvider("aelis.weather", weatherConfig)], MOCK_USER_ID)
+
+		const res = await put(app, "aelis.weather", {
+			enabled: true,
+			config: { units: "metric" },
+			unknownField: "hello",
+		})
+
+		expect(res.status).toBe(400)
+	})
+
+	test("returns 400 when weather config contains unknown fields", async () => {
+		activeStore = createInMemoryStore()
+		const { app } = createApp([createStubProvider("aelis.weather", weatherConfig)], MOCK_USER_ID)
+
+		const res = await put(app, "aelis.weather", {
+			enabled: true,
+			config: { units: "metric", unknownField: "hello" },
+		})
+
+		expect(res.status).toBe(400)
+	})
+
 	test("returns 400 when config fails schema validation", async () => {
 		activeStore = createInMemoryStore()
 		const { app } = createApp([createStubProvider("aelis.weather", weatherConfig)], MOCK_USER_ID)
@@ -541,7 +603,7 @@ describe("PUT /api/sources/:sourceId", () => {
 		expect(session.hasSource("aelis.weather")).toBe(true)
 	})
 
-	test("accepts location source with arbitrary config (no schema)", async () => {
+	test("returns 400 when config is provided for source without schema", async () => {
 		activeStore = createInMemoryStore()
 		const { app } = createApp([createStubProvider("aelis.location")], MOCK_USER_ID)
 
@@ -550,9 +612,29 @@ describe("PUT /api/sources/:sourceId", () => {
 			config: { something: "value" },
 		})
 
+		expect(res.status).toBe(400)
+	})
+
+	test("returns 400 when empty config is provided for source without schema", async () => {
+		activeStore = createInMemoryStore()
+		const { app } = createApp([createStubProvider("aelis.location")], MOCK_USER_ID)
+
+		const res = await put(app, "aelis.location", {
+			enabled: true,
+			config: {},
+		})
+
+		expect(res.status).toBe(400)
+	})
+
+	test("returns 204 without config field for source without schema", async () => {
+		activeStore = createInMemoryStore()
+		const { app } = createApp([createStubProvider("aelis.location")], MOCK_USER_ID)
+
+		const res = await put(app, "aelis.location", {
+			enabled: true,
+		})
+
 		expect(res.status).toBe(204)
-		const row = activeStore.rows.get(`${MOCK_USER_ID}:aelis.location`)
-		expect(row).toBeDefined()
-		expect(row!.config).toEqual({ something: "value" })
 	})
 })

apps/aelis-backend/src/sources/http.ts

@@ -20,15 +20,22 @@ interface SourcesHttpHandlersDeps {
 }
 
 const UpdateSourceConfigRequestBody = type({
+	"+": "reject",
 	"enabled?": "boolean",
 	"config?": "unknown",
 })
 
 const ReplaceSourceConfigRequestBody = type({
+	"+": "reject",
 	enabled: "boolean",
 	config: "unknown",
 })
 
+const ReplaceSourceConfigNoConfigRequestBody = type({
+	"+": "reject",
+	enabled: "boolean",
+})
+
 export function registerSourcesHttpHandlers(
 	app: Hono,
 	{ sessionManager, authSessionMiddleware }: SourcesHttpHandlersDeps,
@@ -69,6 +76,10 @@ async function handleUpdateSource(c: Context<Env>) {
 		return c.json({ error: parsed.summary }, 400)
 	}
 
+	if (!provider.configSchema && "config" in parsed) {
+		return c.json({ error: `Source "${sourceId}" does not accept config` }, 400)
+	}
+
 	const { enabled, config: newConfig } = parsed
 	const user = c.get("user")!
 
@@ -110,12 +121,16 @@ async function handleReplaceSource(c: Context<Env>) {
 		return c.json({ error: "Invalid JSON" }, 400)
 	}
 
-	const parsed = ReplaceSourceConfigRequestBody(body)
+	const schema = provider.configSchema
+		? ReplaceSourceConfigRequestBody
+		: ReplaceSourceConfigNoConfigRequestBody
+	const parsed = schema(body)
 	if (parsed instanceof type.errors) {
 		return c.json({ error: parsed.summary }, 400)
 	}
 
-	const { enabled, config } = parsed
+	const { enabled } = parsed
+	const config = "config" in parsed ? parsed.config : undefined
 	const user = c.get("user")!
 
 	try {

apps/aelis-backend/src/tfl/provider.ts

@@ -8,6 +8,7 @@ export type TflSourceProviderOptions =
 	| { apiKey?: never; client: ITflApi }
 
 export const tflConfig = type({
+	"+": "reject",
 	"lines?": "string[]",
 })
 

apps/aelis-backend/src/weather/provider.ts

@@ -9,6 +9,7 @@ export interface WeatherSourceProviderOptions {
 }
 
 export const weatherConfig = type({
+	"+": "reject",
 	"units?": "'metric' | 'imperial'",
 	"hourlyLimit?": "number",
 	"dailyLimit?": "number",