feat(backend): add location router with tRPC factory pattern

- Add createLocationRouter with location.update mutation
- Refactor tRPC to factory pattern (createTRPC, createTRPCRouter)
- Protected procedure by default (all routes require auth)
- Replace zod with arktype for input validation
- Wire location router in main() with dependency injection

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

apps/aris-backend/package.json

@@ -12,6 +12,9 @@
 		"@aris/core": "workspace:*",
 		"@aris/source-location": "workspace:*",
 		"@aris/source-weatherkit": "workspace:*",
+		"@hono/trpc-server": "^0.3",
+		"@trpc/server": "^11",
+		"arktype": "^2.1.29",
 		"better-auth": "^1",
 		"hono": "^4",
 		"pg": "^8"

apps/aris-backend/src/feed/service.test.ts

@@ -1,162 +0,0 @@
-import { describe, expect, mock, test } from "bun:test"
-
-import { LocationService } from "../location/service.ts"
-import { FeedEngineService } from "./service.ts"
-
-describe("FeedEngineService", () => {
-	test("engineForUser creates engine on first call", () => {
-		const locationService = new LocationService()
-		const service = new FeedEngineService([locationService])
-
-		const engine = service.engineForUser("user-1")
-
-		expect(engine).toBeDefined()
-	})
-
-	test("engineForUser returns same engine for same user", () => {
-		const locationService = new LocationService()
-		const service = new FeedEngineService([locationService])
-
-		const engine1 = service.engineForUser("user-1")
-		const engine2 = service.engineForUser("user-1")
-
-		expect(engine1).toBe(engine2)
-	})
-
-	test("engineForUser returns different engines for different users", () => {
-		const locationService = new LocationService()
-		const service = new FeedEngineService([locationService])
-
-		const engine1 = service.engineForUser("user-1")
-		const engine2 = service.engineForUser("user-2")
-
-		expect(engine1).not.toBe(engine2)
-	})
-
-	test("engineForUser registers sources from all providers", async () => {
-		const locationService = new LocationService()
-		const service = new FeedEngineService([locationService])
-
-		const engine = service.engineForUser("user-1")
-		const result = await engine.refresh()
-
-		expect(result.errors).toHaveLength(0)
-	})
-
-	test("engineForUser works with empty providers array", async () => {
-		const service = new FeedEngineService([])
-
-		const engine = service.engineForUser("user-1")
-		const result = await engine.refresh()
-
-		expect(result.errors).toHaveLength(0)
-		expect(result.items).toHaveLength(0)
-	})
-
-	test("refresh returns feed result", async () => {
-		const locationService = new LocationService()
-		const service = new FeedEngineService([locationService])
-
-		const result = await service.refresh("user-1")
-
-		expect(result).toHaveProperty("context")
-		expect(result).toHaveProperty("items")
-		expect(result).toHaveProperty("errors")
-		expect(result.context.time).toBeInstanceOf(Date)
-	})
-
-	test("refresh uses location from LocationService", async () => {
-		const locationService = new LocationService()
-		const service = new FeedEngineService([locationService])
-		const location = {
-			lat: 51.5074,
-			lng: -0.1278,
-			accuracy: 10,
-			timestamp: new Date(),
-		}
-
-		// Create engine first, then update location
-		service.engineForUser("user-1")
-		locationService.updateUserLocation("user-1", location)
-
-		const result = await service.refresh("user-1")
-
-		expect(result.context.location).toEqual(location)
-	})
-
-	test("subscribe receives updates", async () => {
-		const locationService = new LocationService()
-		const service = new FeedEngineService([locationService])
-		const callback = mock()
-
-		service.subscribe("user-1", callback)
-
-		// Push location to trigger update
-		locationService.updateUserLocation("user-1", {
-			lat: 51.5074,
-			lng: -0.1278,
-			accuracy: 10,
-			timestamp: new Date(),
-		})
-
-		// Wait for async update propagation
-		await new Promise((resolve) => setTimeout(resolve, 10))
-
-		expect(callback).toHaveBeenCalled()
-	})
-
-	test("subscribe returns unsubscribe function", async () => {
-		const locationService = new LocationService()
-		const service = new FeedEngineService([locationService])
-		const callback = mock()
-
-		const unsubscribe = service.subscribe("user-1", callback)
-
-		unsubscribe()
-
-		locationService.updateUserLocation("user-1", {
-			lat: 51.5074,
-			lng: -0.1278,
-			accuracy: 10,
-			timestamp: new Date(),
-		})
-
-		await new Promise((resolve) => setTimeout(resolve, 10))
-
-		expect(callback).not.toHaveBeenCalled()
-	})
-
-	test("removeUser stops engine and removes it", async () => {
-		const locationService = new LocationService()
-		const service = new FeedEngineService([locationService])
-		const callback = mock()
-
-		service.subscribe("user-1", callback)
-
-		service.removeUser("user-1")
-
-		// Push location - should not trigger update since engine is stopped
-		locationService.feedSourceForUser("user-1")
-		locationService.updateUserLocation("user-1", {
-			lat: 51.5074,
-			lng: -0.1278,
-			accuracy: 10,
-			timestamp: new Date(),
-		})
-
-		await new Promise((resolve) => setTimeout(resolve, 10))
-
-		expect(callback).not.toHaveBeenCalled()
-	})
-
-	test("removeUser allows new engine to be created", () => {
-		const locationService = new LocationService()
-		const service = new FeedEngineService([locationService])
-
-		const engine1 = service.engineForUser("user-1")
-		service.removeUser("user-1")
-		const engine2 = service.engineForUser("user-1")
-
-		expect(engine1).not.toBe(engine2)
-	})
-})

apps/aris-backend/src/feed/service.ts

@@ -1,75 +0,0 @@
-import { FeedEngine, type FeedResult, type FeedSource, type FeedSubscriber } from "@aris/core"
-
-/**
- * Provides a FeedSource instance for a user.
- */
-export interface FeedSourceProvider {
-	feedSourceForUser(userId: string): FeedSource
-}
-
-/**
- * Manages FeedEngine instances per user.
- *
- * Receives FeedSource instances from injected providers and wires them
- * into per-user engines. Engines are auto-started on creation.
- */
-export class FeedEngineService {
-	private engines = new Map<string, FeedEngine>()
-
-	constructor(private readonly providers: FeedSourceProvider[]) {}
-
-	/**
-	 * Get or create a FeedEngine for a user.
-	 * Automatically registers sources and starts the engine.
-	 */
-	engineForUser(userId: string): FeedEngine {
-		let engine = this.engines.get(userId)
-		if (!engine) {
-			engine = this.createEngine(userId)
-			this.engines.set(userId, engine)
-		}
-		return engine
-	}
-
-	/**
-	 * Refresh a user's feed.
-	 */
-	async refresh(userId: string): Promise<FeedResult> {
-		const engine = this.engineForUser(userId)
-		return engine.refresh()
-	}
-
-	/**
-	 * Subscribe to feed updates for a user.
-	 * Returns unsubscribe function.
-	 */
-	subscribe(userId: string, callback: FeedSubscriber): () => void {
-		const engine = this.engineForUser(userId)
-		return engine.subscribe(callback)
-	}
-
-	/**
-	 * Remove a user's FeedEngine.
-	 * Stops the engine and cleans up resources.
-	 */
-	removeUser(userId: string): void {
-		const engine = this.engines.get(userId)
-		if (engine) {
-			engine.stop()
-			this.engines.delete(userId)
-		}
-	}
-
-	private createEngine(userId: string): FeedEngine {
-		const engine = new FeedEngine()
-
-		for (const provider of this.providers) {
-			const source = provider.feedSourceForUser(userId)
-			engine.register(source)
-		}
-
-		engine.start()
-
-		return engine
-	}
-}

apps/aris-backend/src/location/router.ts

@@ -0,0 +1,33 @@
+import { TRPCError } from "@trpc/server"
+import { type } from "arktype"
+
+import { UserNotFoundError } from "../lib/error.ts"
+import type { TRPC } from "../trpc/router.ts"
+import type { LocationService } from "./service.ts"
+
+const locationInput = type({
+	lat: "number",
+	lng: "number",
+	accuracy: "number",
+	timestamp: "Date",
+})
+
+export function createLocationRouter(t: TRPC, { locationService }: { locationService: LocationService }) {
+	return t.router({
+		update: t.procedure.input(locationInput).mutation(({ input, ctx }) => {
+			try {
+				locationService.updateUserLocation(ctx.user.id, {
+					lat: input.lat,
+					lng: input.lng,
+					accuracy: input.accuracy,
+					timestamp: input.timestamp,
+				})
+			} catch (error) {
+				if (error instanceof UserNotFoundError) {
+					throw new TRPCError({ code: "NOT_FOUND", message: error.message })
+				}
+				throw error
+			}
+		}),
+	})
+}

apps/aris-backend/src/location/service.ts

@@ -1,13 +1,11 @@
 import { LocationSource, type Location } from "@aris/source-location"
 
-import type { FeedSourceProvider } from "../feed/service.ts"
-
 import { UserNotFoundError } from "../lib/error.ts"
 
 /**
  * Manages LocationSource instances per user.
  */
-export class LocationService implements FeedSourceProvider {
+export class LocationService {
 	private sources = new Map<string, LocationSource>()
 
 	/**

apps/aris-backend/src/server.ts

@@ -1,12 +1,34 @@
+import { trpcServer } from "@hono/trpc-server"
 import { Hono } from "hono"
 
 import { registerAuthHandlers } from "./auth/http.ts"
+import { LocationService } from "./location/service.ts"
+import { createContext } from "./trpc/context.ts"
+import { createTRPCRouter } from "./trpc/router.ts"
 
-const app = new Hono()
+function main() {
+	const locationService = new LocationService()
 
-app.get("/health", (c) => c.json({ status: "ok" }))
+	const trpcRouter = createTRPCRouter({ locationService })
 
-registerAuthHandlers(app)
+	const app = new Hono()
+
+	app.get("/health", (c) => c.json({ status: "ok" }))
+
+	registerAuthHandlers(app)
+
+	app.use(
+		"/trpc/*",
+		trpcServer({
+			router: trpcRouter,
+			createContext,
+		}),
+	)
+
+	return app
+}
+
+const app = main()
 
 export default {
 	port: 3000,

apps/aris-backend/src/trpc/context.ts

@@ -0,0 +1,14 @@
+import type { FetchCreateContextFnOptions } from "@trpc/server/adapters/fetch"
+
+import { auth } from "../auth/index.ts"
+
+export async function createContext(opts: FetchCreateContextFnOptions) {
+	const session = await auth.api.getSession({ headers: opts.req.headers })
+
+	return {
+		user: session?.user ?? null,
+		session: session?.session ?? null,
+	}
+}
+
+export type Context = Awaited<ReturnType<typeof createContext>>

apps/aris-backend/src/trpc/router.ts

@@ -0,0 +1,47 @@
+import { initTRPC, TRPCError } from "@trpc/server"
+
+import { createLocationRouter } from "../location/router.ts"
+import type { LocationService } from "../location/service.ts"
+import type { Context } from "./context.ts"
+
+interface AuthedContext {
+	user: NonNullable<Context["user"]>
+	session: NonNullable<Context["session"]>
+}
+
+function createTRPC() {
+	const t = initTRPC.context<Context>().create()
+
+	const isAuthed = t.middleware(({ ctx, next }) => {
+		if (!ctx.user || !ctx.session) {
+			throw new TRPCError({ code: "UNAUTHORIZED" })
+		}
+		return next({
+			ctx: {
+				user: ctx.user,
+				session: ctx.session,
+			},
+		})
+	})
+
+	return {
+		router: t.router,
+		procedure: t.procedure.use(isAuthed),
+	}
+}
+
+export type TRPC = ReturnType<typeof createTRPC>
+
+export interface TRPCRouterDeps {
+	locationService: LocationService
+}
+
+export function createTRPCRouter({ locationService }: TRPCRouterDeps) {
+	const t = createTRPC()
+
+	return t.router({
+		location: createLocationRouter(t, { locationService }),
+	})
+}
+
+export type TRPCRouter = ReturnType<typeof createTRPCRouter>

bun.lock

@@ -20,6 +20,9 @@
         "@aris/core": "workspace:*",
         "@aris/source-location": "workspace:*",
         "@aris/source-weatherkit": "workspace:*",
+        "@hono/trpc-server": "^0.3",
+        "@trpc/server": "^11",
+        "arktype": "^2.1.29",
         "better-auth": "^1",
         "hono": "^4",
         "pg": "^8",
@@ -91,6 +94,8 @@
 
     "@better-fetch/fetch": ["@better-fetch/fetch@1.1.21", "", {}, "sha512-/ImESw0sskqlVR94jB+5+Pxjf+xBwDZF/N5+y2/q4EqD7IARUTSpPfIo8uf39SYpCxyOCtbyYpUrZ3F/k0zT4A=="],
 
+    "@hono/trpc-server": ["@hono/trpc-server@0.3.4", "", { "peerDependencies": { "@trpc/server": "^10.10.0 || >11.0.0-rc", "hono": ">=4.*" } }, "sha512-xFOPjUPnII70FgicDzOJy1ufIoBTu8eF578zGiDOrYOrYN8CJe140s9buzuPkX+SwJRYK8LjEBHywqZtxdm8aA=="],
+
     "@noble/ciphers": ["@noble/ciphers@2.1.1", "", {}, "sha512-bysYuiVfhxNJuldNXlFEitTVdNnYUc+XNJZd7Qm2a5j1vZHgY+fazadNFWFaMK/2vye0JVlxV3gHmC0WDfAOQw=="],
 
     "@noble/hashes": ["@noble/hashes@2.0.1", "", {}, "sha512-XlOlEbQcE9fmuXxrVTXCTlG2nlRXa9Rj3rr5Ue/+tX+nmkgbX720YHh0VR3hBF9xDvwnb8D2shVGOwNx+ulArw=="],
@@ -129,6 +134,8 @@
 
     "@standard-schema/spec": ["@standard-schema/spec@1.1.0", "", {}, "sha512-l2aFy5jALhniG5HgqrD6jXLi/rUWrKvqN/qJx6yoJsgKhblVd+iqqU4RCXavm/jPityDo5TCvKMnpjKnOriy0w=="],
 
+    "@trpc/server": ["@trpc/server@11.8.1", "", { "peerDependencies": { "typescript": ">=5.7.2" } }, "sha512-P4rzZRpEL7zDFgjxK65IdyH0e41FMFfTkQkuq0BA5tKcr7E6v9/v38DEklCpoDN6sPiB1Sigy/PUEzHENhswDA=="],
+
     "@types/bun": ["@types/bun@1.3.6", "", { "dependencies": { "bun-types": "1.3.6" } }, "sha512-uWCv6FO/8LcpREhenN1d1b6fcspAB+cefwD7uti8C8VffIv0Um08TKMn98FynpTiU38+y2dUO55T11NgDt8VAA=="],
 
     "@types/node": ["@types/node@25.0.9", "", { "dependencies": { "undici-types": "~7.16.0" } }, "sha512-/rpCXHlCWeqClNBwUhDcusJxXYDjZTyE8v5oTO7WbL8eij2nKhUeU89/6xgjU7N4/Vh3He0BtyhJdQbDyhiXAw=="],