Merge pull request #28 from kennethnym/feat/consolidate-backend-services

refactor: consolidate backend services into UserSessionManager

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

@@ -1,10 +1,7 @@
-import { TRPCError } from "@trpc/server"
 import { type } from "arktype"
 
+import type { UserSessionManager } from "../session/index.ts"
 import type { TRPC } from "../trpc/router.ts"
-import type { LocationService } from "./service.ts"
-
-import { UserNotFoundError } from "../lib/error.ts"
 
 const locationInput = type({
 	lat: "number",
@@ -15,23 +12,17 @@ const locationInput = type({
 
 export function createLocationRouter(
 	t: TRPC,
-	{ locationService }: { locationService: LocationService },
+	{ sessionManager }: { sessionManager: UserSessionManager },
 ) {
 	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
-			}
+		update: t.procedure.input(locationInput).mutation(async ({ input, ctx }) => {
+			const session = sessionManager.getOrCreate(ctx.user.id)
+			await session.engine.executeAction("aris.location", "update-location", {
+				lat: input.lat,
+				lng: input.lng,
+				accuracy: input.accuracy,
+				timestamp: input.timestamp,
+			})
 		}),
 	})
 }

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

@@ -1,111 +0,0 @@
-import { describe, expect, test } from "bun:test"
-
-import { UserNotFoundError } from "../lib/error.ts"
-import { LocationService } from "./service.ts"
-
-describe("LocationService", () => {
-	test("feedSourceForUser creates source on first call", () => {
-		const service = new LocationService()
-		const source = service.feedSourceForUser("user-1")
-
-		expect(source).toBeDefined()
-		expect(source.id).toBe("aris.location")
-	})
-
-	test("feedSourceForUser returns same source for same user", () => {
-		const service = new LocationService()
-		const source1 = service.feedSourceForUser("user-1")
-		const source2 = service.feedSourceForUser("user-1")
-
-		expect(source1).toBe(source2)
-	})
-
-	test("feedSourceForUser returns different sources for different users", () => {
-		const service = new LocationService()
-		const source1 = service.feedSourceForUser("user-1")
-		const source2 = service.feedSourceForUser("user-2")
-
-		expect(source1).not.toBe(source2)
-	})
-
-	test("updateUserLocation updates the source", () => {
-		const service = new LocationService()
-		const source = service.feedSourceForUser("user-1")
-		const location = {
-			lat: 51.5074,
-			lng: -0.1278,
-			accuracy: 10,
-			timestamp: new Date(),
-		}
-
-		service.updateUserLocation("user-1", location)
-
-		expect(source.lastLocation).toEqual(location)
-	})
-
-	test("updateUserLocation throws if source does not exist", () => {
-		const service = new LocationService()
-		const location = {
-			lat: 51.5074,
-			lng: -0.1278,
-			accuracy: 10,
-			timestamp: new Date(),
-		}
-
-		expect(() => service.updateUserLocation("user-1", location)).toThrow(UserNotFoundError)
-	})
-
-	test("lastUserLocation returns null for unknown user", () => {
-		const service = new LocationService()
-
-		expect(service.lastUserLocation("unknown")).toBeNull()
-	})
-
-	test("lastUserLocation returns last location", () => {
-		const service = new LocationService()
-		service.feedSourceForUser("user-1")
-		const location1 = {
-			lat: 51.5074,
-			lng: -0.1278,
-			accuracy: 10,
-			timestamp: new Date(),
-		}
-		const location2 = {
-			lat: 52.0,
-			lng: -0.2,
-			accuracy: 5,
-			timestamp: new Date(),
-		}
-
-		service.updateUserLocation("user-1", location1)
-		service.updateUserLocation("user-1", location2)
-
-		expect(service.lastUserLocation("user-1")).toEqual(location2)
-	})
-
-	test("removeUser removes the source", () => {
-		const service = new LocationService()
-		service.feedSourceForUser("user-1")
-		const location = {
-			lat: 51.5074,
-			lng: -0.1278,
-			accuracy: 10,
-			timestamp: new Date(),
-		}
-
-		service.updateUserLocation("user-1", location)
-		service.removeUser("user-1")
-
-		expect(service.lastUserLocation("user-1")).toBeNull()
-	})
-
-	test("removeUser allows new source to be created", () => {
-		const service = new LocationService()
-		const source1 = service.feedSourceForUser("user-1")
-
-		service.removeUser("user-1")
-		const source2 = service.feedSourceForUser("user-1")
-
-		expect(source1).not.toBe(source2)
-	})
-})

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

@@ -1,57 +0,0 @@
-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 {
-	private sources = new Map<string, LocationSource>()
-
-	/**
-	 * Get or create a LocationSource for a user.
-	 * @param userId - The user's unique identifier
-	 * @returns The user's LocationSource instance
-	 */
-	feedSourceForUser(userId: string): LocationSource {
-		let source = this.sources.get(userId)
-		if (!source) {
-			source = new LocationSource()
-			this.sources.set(userId, source)
-		}
-		return source
-	}
-
-	/**
-	 * Update location for a user.
-	 * @param userId - The user's unique identifier
-	 * @param location - The new location data
-	 * @throws {UserNotFoundError} If no source exists for the user
-	 */
-	updateUserLocation(userId: string, location: Location): void {
-		const source = this.sources.get(userId)
-		if (!source) {
-			throw new UserNotFoundError(userId)
-		}
-		source.pushLocation(location)
-	}
-
-	/**
-	 * Get last known location for a user.
-	 * @param userId - The user's unique identifier
-	 * @returns The last location, or null if none exists
-	 */
-	lastUserLocation(userId: string): Location | null {
-		return this.sources.get(userId)?.lastLocation ?? null
-	}
-
-	/**
-	 * Remove a user's LocationSource.
-	 * @param userId - The user's unique identifier
-	 */
-	removeUser(userId: string): void {
-		this.sources.delete(userId)
-	}
-}

apps/aris-backend/src/server.ts

@@ -1,25 +1,27 @@
+import { LocationSource } from "@aris/source-location"
 import { trpcServer } from "@hono/trpc-server"
 import { Hono } from "hono"
 
 import { registerAuthHandlers } from "./auth/http.ts"
-import { LocationService } from "./location/service.ts"
+import { UserSessionManager } from "./session/index.ts"
+import { WeatherSourceProvider } from "./weather/provider.ts"
 import { createContext } from "./trpc/context.ts"
 import { createTRPCRouter } from "./trpc/router.ts"
-import { WeatherService } from "./weather/service.ts"
 
 function main() {
-	const locationService = new LocationService()
+	const sessionManager = new UserSessionManager([
+		() => new LocationSource(),
+		new WeatherSourceProvider({
+			credentials: {
+				privateKey: process.env.WEATHERKIT_PRIVATE_KEY!,
+				keyId: process.env.WEATHERKIT_KEY_ID!,
+				teamId: process.env.WEATHERKIT_TEAM_ID!,
+				serviceId: process.env.WEATHERKIT_SERVICE_ID!,
+			},
+		}),
+	])
 
-	const weatherService = new WeatherService({
-		credentials: {
-			privateKey: process.env.WEATHERKIT_PRIVATE_KEY!,
-			keyId: process.env.WEATHERKIT_KEY_ID!,
-			teamId: process.env.WEATHERKIT_TEAM_ID!,
-			serviceId: process.env.WEATHERKIT_SERVICE_ID!,
-		},
-	})
-
-	const trpcRouter = createTRPCRouter({ locationService, weatherService })
+	const trpcRouter = createTRPCRouter({ sessionManager })
 
 	const app = new Hono()
 

apps/aris-backend/src/session/feed-source-provider.ts

@@ -0,0 +1,9 @@
+import type { FeedSource } from "@aris/core"
+
+export interface FeedSourceProvider {
+	feedSourceForUser(userId: string): FeedSource
+}
+
+export type FeedSourceProviderFn = (userId: string) => FeedSource
+
+export type FeedSourceProviderInput = FeedSourceProvider | FeedSourceProviderFn

apps/aris-backend/src/session/index.ts

@@ -0,0 +1,7 @@
+export type {
+	FeedSourceProvider,
+	FeedSourceProviderFn,
+	FeedSourceProviderInput,
+} from "./feed-source-provider.ts"
+export { UserSession } from "./user-session.ts"
+export { UserSessionManager } from "./user-session-manager.ts"

apps/aris-backend/src/session/user-session-manager.test.ts

@@ -0,0 +1,166 @@
+import { LocationSource } from "@aris/source-location"
+import { describe, expect, mock, test } from "bun:test"
+
+import { WeatherSourceProvider } from "../weather/provider.ts"
+import { UserSessionManager } from "./user-session-manager.ts"
+
+import type { WeatherKitClient, WeatherKitResponse } from "@aris/source-weatherkit"
+
+const mockWeatherClient: WeatherKitClient = {
+	fetch: async () => ({}) as WeatherKitResponse,
+}
+
+describe("UserSessionManager", () => {
+	test("getOrCreate creates session on first call", () => {
+		const manager = new UserSessionManager([() => new LocationSource()])
+
+		const session = manager.getOrCreate("user-1")
+
+		expect(session).toBeDefined()
+		expect(session.engine).toBeDefined()
+	})
+
+	test("getOrCreate returns same session for same user", () => {
+		const manager = new UserSessionManager([() => new LocationSource()])
+
+		const session1 = manager.getOrCreate("user-1")
+		const session2 = manager.getOrCreate("user-1")
+
+		expect(session1).toBe(session2)
+	})
+
+	test("getOrCreate returns different sessions for different users", () => {
+		const manager = new UserSessionManager([() => new LocationSource()])
+
+		const session1 = manager.getOrCreate("user-1")
+		const session2 = manager.getOrCreate("user-2")
+
+		expect(session1).not.toBe(session2)
+	})
+
+	test("each user gets independent source instances", () => {
+		const manager = new UserSessionManager([() => new LocationSource()])
+
+		const session1 = manager.getOrCreate("user-1")
+		const session2 = manager.getOrCreate("user-2")
+
+		const source1 = session1.getSource<LocationSource>("aris.location")
+		const source2 = session2.getSource<LocationSource>("aris.location")
+
+		expect(source1).not.toBe(source2)
+	})
+
+	test("remove destroys session and allows re-creation", () => {
+		const manager = new UserSessionManager([() => new LocationSource()])
+
+		const session1 = manager.getOrCreate("user-1")
+		manager.remove("user-1")
+		const session2 = manager.getOrCreate("user-1")
+
+		expect(session1).not.toBe(session2)
+	})
+
+	test("remove is no-op for unknown user", () => {
+		const manager = new UserSessionManager([() => new LocationSource()])
+
+		expect(() => manager.remove("unknown")).not.toThrow()
+	})
+
+	test("accepts function providers", async () => {
+		const manager = new UserSessionManager([() => new LocationSource()])
+
+		const session = manager.getOrCreate("user-1")
+		const result = await session.engine.refresh()
+
+		expect(result.errors).toHaveLength(0)
+	})
+
+	test("accepts object providers", () => {
+		const provider = new WeatherSourceProvider({ client: mockWeatherClient })
+		const manager = new UserSessionManager([() => new LocationSource(), provider])
+
+		const session = manager.getOrCreate("user-1")
+
+		expect(session.getSource("aris.weather")).toBeDefined()
+	})
+
+	test("accepts mixed providers", () => {
+		const provider = new WeatherSourceProvider({ client: mockWeatherClient })
+		const manager = new UserSessionManager([() => new LocationSource(), provider])
+
+		const session = manager.getOrCreate("user-1")
+
+		expect(session.getSource("aris.location")).toBeDefined()
+		expect(session.getSource("aris.weather")).toBeDefined()
+	})
+
+	test("refresh returns feed result through session", async () => {
+		const manager = new UserSessionManager([() => new LocationSource()])
+
+		const session = manager.getOrCreate("user-1")
+		const result = await session.engine.refresh()
+
+		expect(result).toHaveProperty("context")
+		expect(result).toHaveProperty("items")
+		expect(result).toHaveProperty("errors")
+		expect(result.context.time).toBeInstanceOf(Date)
+	})
+
+	test("location update via executeAction works", async () => {
+		const manager = new UserSessionManager([() => new LocationSource()])
+
+		const session = manager.getOrCreate("user-1")
+		await session.engine.executeAction("aris.location", "update-location", {
+			lat: 51.5074,
+			lng: -0.1278,
+			accuracy: 10,
+			timestamp: new Date(),
+		})
+
+		const source = session.getSource<LocationSource>("aris.location")
+		expect(source?.lastLocation?.lat).toBe(51.5074)
+	})
+
+	test("subscribe receives updates after location push", async () => {
+		const manager = new UserSessionManager([() => new LocationSource()])
+		const callback = mock()
+
+		const session = manager.getOrCreate("user-1")
+		session.engine.subscribe(callback)
+
+		await session.engine.executeAction("aris.location", "update-location", {
+			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("remove stops reactive updates", async () => {
+		const manager = new UserSessionManager([() => new LocationSource()])
+		const callback = mock()
+
+		const session = manager.getOrCreate("user-1")
+		session.engine.subscribe(callback)
+
+		manager.remove("user-1")
+
+		// Create new session and push location — old callback should not fire
+		const session2 = manager.getOrCreate("user-1")
+		await session2.engine.executeAction("aris.location", "update-location", {
+			lat: 51.5074,
+			lng: -0.1278,
+			accuracy: 10,
+			timestamp: new Date(),
+		})
+
+		await new Promise((resolve) => setTimeout(resolve, 10))
+
+		expect(callback).not.toHaveBeenCalled()
+	})
+})

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

@@ -0,0 +1,31 @@
+import type { FeedSourceProviderInput } from "./feed-source-provider.ts"
+import { UserSession } from "./user-session.ts"
+
+export class UserSessionManager {
+	private sessions = new Map<string, UserSession>()
+	private readonly providers: FeedSourceProviderInput[]
+
+	constructor(providers: FeedSourceProviderInput[]) {
+		this.providers = providers
+	}
+
+	getOrCreate(userId: string): UserSession {
+		let session = this.sessions.get(userId)
+		if (!session) {
+			const sources = this.providers.map((p) =>
+				typeof p === "function" ? p(userId) : p.feedSourceForUser(userId),
+			)
+			session = new UserSession(sources)
+			this.sessions.set(userId, session)
+		}
+		return session
+	}
+
+	remove(userId: string): void {
+		const session = this.sessions.get(userId)
+		if (session) {
+			session.destroy()
+			this.sessions.delete(userId)
+		}
+	}
+}

apps/aris-backend/src/session/user-session.test.ts

@@ -0,0 +1,72 @@
+import type { ActionDefinition, Context, FeedSource } from "@aris/core"
+
+import { LocationSource } from "@aris/source-location"
+import { describe, expect, test } from "bun:test"
+
+import { UserSession } from "./user-session.ts"
+
+function createStubSource(id: string): FeedSource {
+	return {
+		id,
+		async listActions(): Promise<Record<string, ActionDefinition>> {
+			return {}
+		},
+		async executeAction(): Promise<unknown> {
+			return undefined
+		},
+		async fetchContext(): Promise<Partial<Context> | null> {
+			return null
+		},
+		async fetchItems() {
+			return []
+		},
+	}
+}
+
+describe("UserSession", () => {
+	test("registers sources and starts engine", async () => {
+		const session = new UserSession([createStubSource("test-a"), createStubSource("test-b")])
+
+		const result = await session.engine.refresh()
+
+		expect(result.errors).toHaveLength(0)
+	})
+
+	test("getSource returns registered source", () => {
+		const location = new LocationSource()
+		const session = new UserSession([location])
+
+		const result = session.getSource<LocationSource>("aris.location")
+
+		expect(result).toBe(location)
+	})
+
+	test("getSource returns undefined for unknown source", () => {
+		const session = new UserSession([createStubSource("test")])
+
+		expect(session.getSource("unknown")).toBeUndefined()
+	})
+
+	test("destroy stops engine and clears sources", () => {
+		const session = new UserSession([createStubSource("test")])
+
+		session.destroy()
+
+		expect(session.getSource("test")).toBeUndefined()
+	})
+
+	test("engine.executeAction routes to correct source", async () => {
+		const location = new LocationSource()
+		const session = new UserSession([location])
+
+		await session.engine.executeAction("aris.location", "update-location", {
+			lat: 51.5,
+			lng: -0.1,
+			accuracy: 10,
+			timestamp: new Date(),
+		})
+
+		expect(location.lastLocation).toBeDefined()
+		expect(location.lastLocation!.lat).toBe(51.5)
+	})
+})

apps/aris-backend/src/session/user-session.ts

@@ -0,0 +1,24 @@
+import { FeedEngine, type FeedSource } from "@aris/core"
+
+export class UserSession {
+	readonly engine: FeedEngine
+	private sources = new Map<string, FeedSource>()
+
+	constructor(sources: FeedSource[]) {
+		this.engine = new FeedEngine()
+		for (const source of sources) {
+			this.sources.set(source.id, source)
+			this.engine.register(source)
+		}
+		this.engine.start()
+	}
+
+	getSource<T extends FeedSource>(sourceId: string): T | undefined {
+		return this.sources.get(sourceId) as T | undefined
+	}
+
+	destroy(): void {
+		this.engine.stop()
+		this.sources.clear()
+	}
+}

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

@@ -0,0 +1,19 @@
+import { TflSource, type ITflApi } from "@aris/source-tfl"
+
+import type { FeedSourceProvider } from "../session/feed-source-provider.ts"
+
+export type TflSourceProviderOptions =
+	| { apiKey: string; client?: never }
+	| { apiKey?: never; client: ITflApi }
+
+export class TflSourceProvider implements FeedSourceProvider {
+	private readonly options: TflSourceProviderOptions
+
+	constructor(options: TflSourceProviderOptions) {
+		this.options = options
+	}
+
+	feedSourceForUser(_userId: string): TflSource {
+		return new TflSource(this.options)
+	}
+}

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

@@ -1,206 +0,0 @@
-import type { Context } from "@aris/core"
-import type { ITflApi, StationLocation, TflLineId, TflLineStatus } from "@aris/source-tfl"
-
-import { describe, expect, test } from "bun:test"
-
-import { UserNotFoundError } from "../lib/error.ts"
-import { TflService } from "./service.ts"
-
-class StubTflApi implements ITflApi {
-	private statuses: TflLineStatus[]
-
-	constructor(statuses: TflLineStatus[] = []) {
-		this.statuses = statuses
-	}
-
-	async fetchLineStatuses(lines?: TflLineId[]): Promise<TflLineStatus[]> {
-		if (lines) {
-			return this.statuses.filter((s) => lines.includes(s.lineId))
-		}
-		return this.statuses
-	}
-
-	async fetchStations(): Promise<StationLocation[]> {
-		return [
-			{
-				id: "940GZZLUKSX",
-				name: "King's Cross",
-				lat: 51.5308,
-				lng: -0.1238,
-				lines: ["northern", "victoria"],
-			},
-		]
-	}
-}
-
-function createContext(): Context {
-	return { time: new Date("2026-01-15T12:00:00Z") }
-}
-
-const sampleStatuses: TflLineStatus[] = [
-	{
-		lineId: "northern",
-		lineName: "Northern",
-		severity: "minor-delays",
-		description: "Minor delays on the Northern line",
-	},
-	{
-		lineId: "victoria",
-		lineName: "Victoria",
-		severity: "major-delays",
-		description: "Severe delays on the Victoria line",
-	},
-	{
-		lineId: "central",
-		lineName: "Central",
-		severity: "closure",
-		description: "Central line suspended",
-	},
-]
-
-describe("TflService", () => {
-	test("feedSourceForUser creates source on first call", () => {
-		const service = new TflService(new StubTflApi())
-		const source = service.feedSourceForUser("user-1")
-
-		expect(source).toBeDefined()
-		expect(source.id).toBe("aris.tfl")
-	})
-
-	test("feedSourceForUser returns same source for same user", () => {
-		const service = new TflService(new StubTflApi())
-		const source1 = service.feedSourceForUser("user-1")
-		const source2 = service.feedSourceForUser("user-1")
-
-		expect(source1).toBe(source2)
-	})
-
-	test("feedSourceForUser returns different sources for different users", () => {
-		const service = new TflService(new StubTflApi())
-		const source1 = service.feedSourceForUser("user-1")
-		const source2 = service.feedSourceForUser("user-2")
-
-		expect(source1).not.toBe(source2)
-	})
-
-	test("updateLinesOfInterest mutates the existing source in place", () => {
-		const service = new TflService(new StubTflApi())
-		const original = service.feedSourceForUser("user-1")
-
-		service.updateLinesOfInterest("user-1", ["northern", "victoria"])
-		const after = service.feedSourceForUser("user-1")
-
-		expect(after).toBe(original)
-	})
-
-	test("updateLinesOfInterest throws if source does not exist", () => {
-		const service = new TflService(new StubTflApi())
-
-		expect(() => service.updateLinesOfInterest("user-1", ["northern"])).toThrow(UserNotFoundError)
-	})
-
-	test("removeUser removes the source", () => {
-		const service = new TflService(new StubTflApi())
-		const source1 = service.feedSourceForUser("user-1")
-
-		service.removeUser("user-1")
-		const source2 = service.feedSourceForUser("user-1")
-
-		expect(source1).not.toBe(source2)
-	})
-
-	test("removeUser clears line configuration", async () => {
-		const api = new StubTflApi(sampleStatuses)
-		const service = new TflService(api)
-		service.feedSourceForUser("user-1")
-		service.updateLinesOfInterest("user-1", ["northern"])
-
-		service.removeUser("user-1")
-		const items = await service.feedSourceForUser("user-1").fetchItems(createContext())
-
-		expect(items.length).toBe(3)
-	})
-
-	test("shares single api instance across users", () => {
-		const api = new StubTflApi()
-		const service = new TflService(api)
-
-		service.feedSourceForUser("user-1")
-		service.feedSourceForUser("user-2")
-
-		expect(service.feedSourceForUser("user-1").id).toBe("aris.tfl")
-		expect(service.feedSourceForUser("user-2").id).toBe("aris.tfl")
-	})
-
-	describe("returned source fetches items", () => {
-		test("source returns feed items from api", async () => {
-			const api = new StubTflApi(sampleStatuses)
-			const service = new TflService(api)
-			const source = service.feedSourceForUser("user-1")
-
-			const items = await source.fetchItems(createContext())
-
-			expect(items.length).toBe(3)
-			for (const item of items) {
-				expect(item.type).toBe("tfl-alert")
-				expect(item.id).toMatch(/^tfl-alert-/)
-				expect(typeof item.priority).toBe("number")
-				expect(item.timestamp).toBeInstanceOf(Date)
-			}
-		})
-
-		test("source returns items sorted by priority descending", async () => {
-			const api = new StubTflApi(sampleStatuses)
-			const service = new TflService(api)
-			const source = service.feedSourceForUser("user-1")
-
-			const items = await source.fetchItems(createContext())
-
-			for (let i = 1; i < items.length; i++) {
-				expect(items[i - 1]!.priority).toBeGreaterThanOrEqual(items[i]!.priority)
-			}
-		})
-
-		test("source returns empty array when no disruptions", async () => {
-			const api = new StubTflApi([])
-			const service = new TflService(api)
-			const source = service.feedSourceForUser("user-1")
-
-			const items = await source.fetchItems(createContext())
-
-			expect(items).toEqual([])
-		})
-
-		test("updateLinesOfInterest filters items to configured lines", async () => {
-			const api = new StubTflApi(sampleStatuses)
-			const service = new TflService(api)
-
-			const before = await service.feedSourceForUser("user-1").fetchItems(createContext())
-			expect(before.length).toBe(3)
-
-			service.updateLinesOfInterest("user-1", ["northern"])
-			const after = await service.feedSourceForUser("user-1").fetchItems(createContext())
-
-			expect(after.length).toBe(1)
-			expect(after[0]!.data.line).toBe("northern")
-		})
-
-		test("different users get independent line configs", async () => {
-			const api = new StubTflApi(sampleStatuses)
-			const service = new TflService(api)
-			service.feedSourceForUser("user-1")
-			service.feedSourceForUser("user-2")
-
-			service.updateLinesOfInterest("user-1", ["northern"])
-			service.updateLinesOfInterest("user-2", ["central"])
-
-			const items1 = await service.feedSourceForUser("user-1").fetchItems(createContext())
-			const items2 = await service.feedSourceForUser("user-2").fetchItems(createContext())
-
-			expect(items1.length).toBe(1)
-			expect(items1[0]!.data.line).toBe("northern")
-			expect(items2.length).toBe(1)
-			expect(items2[0]!.data.line).toBe("central")
-		})
-	})
-})

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

@@ -1,40 +0,0 @@
-import { TflSource, type ITflApi, type TflLineId } from "@aris/source-tfl"
-
-import type { FeedSourceProvider } from "../feed/service.ts"
-
-import { UserNotFoundError } from "../lib/error.ts"
-
-/**
- * Manages per-user TflSource instances with individual line configuration.
- */
-export class TflService implements FeedSourceProvider {
-	private sources = new Map<string, TflSource>()
-
-	constructor(private readonly api: ITflApi) {}
-
-	feedSourceForUser(userId: string): TflSource {
-		let source = this.sources.get(userId)
-		if (!source) {
-			source = new TflSource({ client: this.api })
-			this.sources.set(userId, source)
-		}
-		return source
-	}
-
-	/**
-	 * Update monitored lines for a user. Mutates the existing TflSource
-	 * so that references held by FeedEngine remain valid.
-	 * @throws {UserNotFoundError} If no source exists for the user
-	 */
-	updateLinesOfInterest(userId: string, lines: TflLineId[]): void {
-		const source = this.sources.get(userId)
-		if (!source) {
-			throw new UserNotFoundError(userId)
-		}
-		source.setLinesOfInterest(lines)
-	}
-
-	removeUser(userId: string): void {
-		this.sources.delete(userId)
-	}
-}

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

@@ -1,16 +1,26 @@
 import { initTRPC, TRPCError } from "@trpc/server"
 
-import type { LocationService } from "../location/service.ts"
-import type { WeatherService } from "../weather/service.ts"
+import type { UserSessionManager } from "../session/index.ts"
 import type { Context } from "./context.ts"
 
 import { createLocationRouter } from "../location/router.ts"
 
-interface AuthedContext {
-	user: NonNullable<Context["user"]>
-	session: NonNullable<Context["session"]>
+export type TRPC = ReturnType<typeof createTRPC>
+
+export interface TRPCRouterDeps {
+	sessionManager: UserSessionManager
 }
 
+export function createTRPCRouter({ sessionManager }: TRPCRouterDeps) {
+	const t = createTRPC()
+
+	return t.router({
+		location: createLocationRouter(t, { sessionManager }),
+	})
+}
+
+export type TRPCRouter = ReturnType<typeof createTRPCRouter>
+
 function createTRPC() {
 	const t = initTRPC.context<Context>().create()
 
@@ -32,19 +42,3 @@ function createTRPC() {
 	}
 }
 
-export type TRPC = ReturnType<typeof createTRPC>
-
-export interface TRPCRouterDeps {
-	locationService: LocationService
-	weatherService: WeatherService
-}
-
-export function createTRPCRouter({ locationService }: TRPCRouterDeps) {
-	const t = createTRPC()
-
-	return t.router({
-		location: createLocationRouter(t, { locationService }),
-	})
-}
-
-export type TRPCRouter = ReturnType<typeof createTRPCRouter>

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

@@ -0,0 +1,15 @@
+import { WeatherSource, type WeatherSourceOptions } from "@aris/source-weatherkit"
+
+import type { FeedSourceProvider } from "../session/feed-source-provider.ts"
+
+export class WeatherSourceProvider implements FeedSourceProvider {
+	private readonly options: WeatherSourceOptions
+
+	constructor(options: WeatherSourceOptions) {
+		this.options = options
+	}
+
+	feedSourceForUser(_userId: string): WeatherSource {
+		return new WeatherSource(this.options)
+	}
+}

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

@@ -1,116 +0,0 @@
-import type { Context } from "@aris/core"
-
-import { LocationKey } from "@aris/source-location"
-import {
-	Units,
-	WeatherFeedItemType,
-	type WeatherKitClient,
-	type WeatherKitResponse,
-} from "@aris/source-weatherkit"
-import { describe, expect, test } from "bun:test"
-
-import fixture from "../../../../packages/aris-source-weatherkit/fixtures/san-francisco.json"
-import { WeatherService } from "./service.ts"
-
-const mockClient = createMockClient(fixture.response as WeatherKitResponse)
-
-function createMockClient(response: WeatherKitResponse): WeatherKitClient {
-	return {
-		fetch: async () => response,
-	}
-}
-
-function createMockContext(location?: { lat: number; lng: number }): Context {
-	const ctx: Context = { time: new Date("2026-01-17T00:00:00Z") }
-	if (location) {
-		ctx[LocationKey] = { ...location, accuracy: 10, timestamp: new Date() }
-	}
-	return ctx
-}
-
-describe("WeatherService", () => {
-	test("feedSourceForUser creates source on first call", () => {
-		const service = new WeatherService({ client: mockClient })
-		const source = service.feedSourceForUser("user-1")
-
-		expect(source).toBeDefined()
-		expect(source.id).toBe("aris.weather")
-	})
-
-	test("feedSourceForUser returns same source for same user", () => {
-		const service = new WeatherService({ client: mockClient })
-		const source1 = service.feedSourceForUser("user-1")
-		const source2 = service.feedSourceForUser("user-1")
-
-		expect(source1).toBe(source2)
-	})
-
-	test("feedSourceForUser returns different sources for different users", () => {
-		const service = new WeatherService({ client: mockClient })
-		const source1 = service.feedSourceForUser("user-1")
-		const source2 = service.feedSourceForUser("user-2")
-
-		expect(source1).not.toBe(source2)
-	})
-
-	test("feedSourceForUser applies hourly and daily limits", async () => {
-		const service = new WeatherService({
-			client: mockClient,
-			hourlyLimit: 3,
-			dailyLimit: 2,
-		})
-		const source = service.feedSourceForUser("user-1")
-		const context = createMockContext({ lat: 37.7749, lng: -122.4194 })
-
-		const items = await source.fetchItems(context)
-
-		const hourly = items.filter((i) => i.type === WeatherFeedItemType.hourly)
-		const daily = items.filter((i) => i.type === WeatherFeedItemType.daily)
-
-		expect(hourly).toHaveLength(3)
-		expect(daily).toHaveLength(2)
-	})
-
-	test("feedSourceForUser applies units", async () => {
-		const service = new WeatherService({
-			client: mockClient,
-			units: Units.imperial,
-		})
-		const source = service.feedSourceForUser("user-1")
-		const context = createMockContext({ lat: 37.7749, lng: -122.4194 })
-
-		const items = await source.fetchItems(context)
-		const current = items.find((i) => i.type === WeatherFeedItemType.current)
-
-		expect(current).toBeDefined()
-		// Fixture has ~15.87°C, imperial should be ~60.6°F
-		expect(current!.data.temperature).toBeGreaterThan(50)
-	})
-
-	test("removeUser removes the source", () => {
-		const service = new WeatherService({ client: mockClient })
-		service.feedSourceForUser("user-1")
-
-		service.removeUser("user-1")
-
-		// After removal, feedSourceForUser should create a new instance
-		const source2 = service.feedSourceForUser("user-1")
-		expect(source2).toBeDefined()
-	})
-
-	test("removeUser allows new source to be created", () => {
-		const service = new WeatherService({ client: mockClient })
-		const source1 = service.feedSourceForUser("user-1")
-
-		service.removeUser("user-1")
-		const source2 = service.feedSourceForUser("user-1")
-
-		expect(source1).not.toBe(source2)
-	})
-
-	test("removeUser is no-op for unknown user", () => {
-		const service = new WeatherService({ client: mockClient })
-
-		expect(() => service.removeUser("unknown")).not.toThrow()
-	})
-})

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

@@ -1,40 +0,0 @@
-import { WeatherSource, type WeatherSourceOptions } from "@aris/source-weatherkit"
-
-import type { FeedSourceProvider } from "../feed/service.ts"
-
-/**
- * Options forwarded to every per-user WeatherSource.
- * Must include either `credentials` or `client` (same requirement as WeatherSourceOptions).
- */
-export type WeatherServiceOptions = WeatherSourceOptions
-
-/**
- * Manages WeatherSource instances per user.
- */
-export class WeatherService implements FeedSourceProvider {
-	private sources = new Map<string, WeatherSource>()
-	private readonly options: WeatherServiceOptions
-
-	constructor(options: WeatherServiceOptions) {
-		this.options = options
-	}
-
-	/**
-	 * Get or create a WeatherSource for a user.
-	 */
-	feedSourceForUser(userId: string): WeatherSource {
-		let source = this.sources.get(userId)
-		if (!source) {
-			source = new WeatherSource(this.options)
-			this.sources.set(userId, source)
-		}
-		return source
-	}
-
-	/**
-	 * Remove a user's WeatherSource.
-	 */
-	removeUser(userId: string): void {
-		this.sources.delete(userId)
-	}
-}