refactor: rename aris to aelis (#59)

Rename all references across the codebase: package names,
imports, source IDs, directory names, docs, and configs.

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

packages/aelis-core/src/feed-engine.test.ts

@@ -0,0 +1,931 @@
+import { describe, expect, test } from "bun:test"
+
+import type { ActionDefinition, ContextEntry, ContextKey, FeedItem, FeedSource } from "./index"
+
+import { FeedEngine } from "./feed-engine"
+import { Context, TimeRelevance, UnknownActionError, contextKey } from "./index"
+
+// No-op action methods for test sources
+const noActions = {
+	async listActions(): Promise<Record<string, ActionDefinition>> {
+		return {}
+	},
+	async executeAction(actionId: string): Promise<void> {
+		throw new UnknownActionError(actionId)
+	},
+}
+
+// =============================================================================
+// CONTEXT KEYS
+// =============================================================================
+
+interface Location {
+	lat: number
+	lng: number
+}
+
+interface Weather {
+	temperature: number
+	condition: string
+}
+
+const LocationKey: ContextKey<Location> = contextKey("location")
+const WeatherKey: ContextKey<Weather> = contextKey("weather")
+
+// =============================================================================
+// FEED ITEMS
+// =============================================================================
+
+type WeatherFeedItem = FeedItem<"weather", { temperature: number; condition: string }>
+type AlertFeedItem = FeedItem<"alert", { message: string }>
+
+// =============================================================================
+// TEST HELPERS
+// =============================================================================
+
+interface SimulatedLocationSource extends FeedSource {
+	simulateUpdate(location: Location): void
+}
+
+function createLocationSource(): SimulatedLocationSource {
+	let callback: ((entries: readonly ContextEntry[]) => void) | null = null
+	let currentLocation: Location = { lat: 0, lng: 0 }
+
+	return {
+		id: "location",
+		...noActions,
+
+		onContextUpdate(cb) {
+			callback = cb
+			return () => {
+				callback = null
+			}
+		},
+
+		async fetchContext() {
+			return [[LocationKey, currentLocation]]
+		},
+
+		simulateUpdate(location: Location) {
+			currentLocation = location
+			callback?.([[LocationKey, location]])
+		},
+	}
+}
+
+function createWeatherSource(
+	fetchWeather: (location: Location) => Promise<Weather> = async () => ({
+		temperature: 20,
+		condition: "sunny",
+	}),
+): FeedSource<WeatherFeedItem> {
+	return {
+		id: "weather",
+		dependencies: ["location"],
+		...noActions,
+
+		async fetchContext(context) {
+			const location = context.get(LocationKey)
+			if (!location) return null
+
+			const weather = await fetchWeather(location)
+			return [[WeatherKey, weather]]
+		},
+
+		async fetchItems(context) {
+			const weather = context.get(WeatherKey)
+			if (!weather) return []
+
+			return [
+				{
+					id: `weather-${Date.now()}`,
+					type: "weather",
+					timestamp: new Date(),
+					data: {
+						temperature: weather.temperature,
+						condition: weather.condition,
+					},
+					signals: { urgency: 0.5, timeRelevance: TimeRelevance.Ambient },
+				},
+			]
+		},
+	}
+}
+
+function createAlertSource(): FeedSource<AlertFeedItem> {
+	return {
+		id: "alert",
+		dependencies: ["weather"],
+		...noActions,
+
+		async fetchContext() {
+			return null
+		},
+
+		async fetchItems(context) {
+			const weather = context.get(WeatherKey)
+			if (!weather) return []
+
+			if (weather.condition === "storm") {
+				return [
+					{
+						id: "alert-storm",
+						type: "alert",
+						timestamp: new Date(),
+						data: { message: "Storm warning!" },
+						signals: { urgency: 1.0, timeRelevance: TimeRelevance.Imminent },
+					},
+				]
+			}
+
+			return []
+		},
+	}
+}
+
+// =============================================================================
+// TESTS
+// =============================================================================
+
+describe("FeedEngine", () => {
+	describe("registration", () => {
+		test("registers sources", () => {
+			const engine = new FeedEngine()
+			const location = createLocationSource()
+
+			engine.register(location)
+
+			// Can refresh without error
+			expect(engine.refresh()).resolves.toBeDefined()
+		})
+
+		test("unregisters sources", async () => {
+			const engine = new FeedEngine()
+			const location = createLocationSource()
+
+			engine.register(location)
+			engine.unregister("location")
+
+			const result = await engine.refresh()
+			expect(result.items).toHaveLength(0)
+		})
+
+		test("allows chained registration", () => {
+			const engine = new FeedEngine()
+				.register(createLocationSource())
+				.register(createWeatherSource())
+				.register(createAlertSource())
+
+			expect(engine.refresh()).resolves.toBeDefined()
+		})
+	})
+
+	describe("graph validation", () => {
+		test("throws on missing dependency", async () => {
+			const engine = new FeedEngine()
+			const orphan: FeedSource = {
+				id: "orphan",
+				dependencies: ["nonexistent"],
+				...noActions,
+				async fetchContext() {
+					return null
+				},
+			}
+
+			engine.register(orphan)
+
+			await expect(engine.refresh()).rejects.toThrow(
+				'Source "orphan" depends on "nonexistent" which is not registered',
+			)
+		})
+
+		test("throws on circular dependency", async () => {
+			const engine = new FeedEngine()
+			const a: FeedSource = {
+				id: "a",
+				dependencies: ["b"],
+				...noActions,
+				async fetchContext() {
+					return null
+				},
+			}
+			const b: FeedSource = {
+				id: "b",
+				dependencies: ["a"],
+				...noActions,
+				async fetchContext() {
+					return null
+				},
+			}
+
+			engine.register(a).register(b)
+
+			await expect(engine.refresh()).rejects.toThrow("Circular dependency detected: a → b → a")
+		})
+
+		test("throws on longer cycles", async () => {
+			const engine = new FeedEngine()
+			const a: FeedSource = {
+				id: "a",
+				dependencies: ["c"],
+				...noActions,
+				async fetchContext() {
+					return null
+				},
+			}
+			const b: FeedSource = {
+				id: "b",
+				dependencies: ["a"],
+				...noActions,
+				async fetchContext() {
+					return null
+				},
+			}
+			const c: FeedSource = {
+				id: "c",
+				dependencies: ["b"],
+				...noActions,
+				async fetchContext() {
+					return null
+				},
+			}
+
+			engine.register(a).register(b).register(c)
+
+			await expect(engine.refresh()).rejects.toThrow("Circular dependency detected")
+		})
+	})
+
+	describe("refresh", () => {
+		test("runs fetchContext in dependency order", async () => {
+			const order: string[] = []
+
+			const location: FeedSource = {
+				id: "location",
+				...noActions,
+				async fetchContext() {
+					order.push("location")
+					return [[LocationKey, { lat: 51.5, lng: -0.1 }]]
+				},
+			}
+
+			const weather: FeedSource = {
+				id: "weather",
+				dependencies: ["location"],
+				...noActions,
+				async fetchContext(ctx) {
+					order.push("weather")
+					const loc = ctx.get(LocationKey)
+					expect(loc).toBeDefined()
+					return [[WeatherKey, { temperature: 20, condition: "sunny" }]]
+				},
+			}
+
+			const engine = new FeedEngine().register(weather).register(location)
+
+			await engine.refresh()
+
+			expect(order).toEqual(["location", "weather"])
+		})
+
+		test("accumulates context across sources", async () => {
+			const location = createLocationSource()
+			location.simulateUpdate({ lat: 51.5, lng: -0.1 })
+
+			const weather = createWeatherSource()
+
+			const engine = new FeedEngine().register(location).register(weather)
+
+			const { context } = await engine.refresh()
+
+			expect(context.get(LocationKey)).toEqual({
+				lat: 51.5,
+				lng: -0.1,
+			})
+			expect(context.get(WeatherKey)).toEqual({
+				temperature: 20,
+				condition: "sunny",
+			})
+		})
+
+		test("collects items from all sources", async () => {
+			const location = createLocationSource()
+			location.simulateUpdate({ lat: 51.5, lng: -0.1 })
+
+			const weather = createWeatherSource()
+
+			const engine = new FeedEngine().register(location).register(weather)
+
+			const { items } = await engine.refresh()
+
+			expect(items).toHaveLength(1)
+			expect(items[0]!.type).toBe("weather")
+		})
+
+		test("returns items in source graph order (no engine-level sorting)", async () => {
+			const location = createLocationSource()
+			location.simulateUpdate({ lat: 51.5, lng: -0.1 })
+
+			const weather = createWeatherSource(async () => ({
+				temperature: 15,
+				condition: "storm",
+			}))
+
+			const alert = createAlertSource()
+
+			const engine = new FeedEngine().register(location).register(weather).register(alert)
+
+			const { items } = await engine.refresh()
+
+			expect(items).toHaveLength(2)
+			// Items returned in topological order (weather before alert)
+			expect(items[0]!.type).toBe("weather")
+			expect(items[1]!.type).toBe("alert")
+			// Signals are preserved for post-processors to consume
+			expect(items[0]!.signals?.urgency).toBe(0.5)
+			expect(items[1]!.signals?.urgency).toBe(1.0)
+		})
+
+		test("handles missing upstream context gracefully", async () => {
+			const location: FeedSource = {
+				id: "location",
+				...noActions,
+				async fetchContext() {
+					return null // No location available
+				},
+			}
+
+			const weather = createWeatherSource()
+
+			const engine = new FeedEngine().register(location).register(weather)
+
+			const { context, items } = await engine.refresh()
+
+			expect(context.get(WeatherKey)).toBeUndefined()
+			expect(items).toHaveLength(0)
+		})
+
+		test("captures errors from fetchContext", async () => {
+			const failing: FeedSource = {
+				id: "failing",
+				...noActions,
+				async fetchContext() {
+					throw new Error("Context fetch failed")
+				},
+			}
+
+			const engine = new FeedEngine().register(failing)
+
+			const { errors } = await engine.refresh()
+
+			expect(errors).toHaveLength(1)
+			expect(errors[0]!.sourceId).toBe("failing")
+			expect(errors[0]!.error.message).toBe("Context fetch failed")
+		})
+
+		test("captures errors from fetchItems", async () => {
+			const failing: FeedSource = {
+				id: "failing",
+				...noActions,
+				async fetchContext() {
+					return null
+				},
+				async fetchItems() {
+					throw new Error("Items fetch failed")
+				},
+			}
+
+			const engine = new FeedEngine().register(failing)
+
+			const { errors } = await engine.refresh()
+
+			expect(errors).toHaveLength(1)
+			expect(errors[0]!.sourceId).toBe("failing")
+			expect(errors[0]!.error.message).toBe("Items fetch failed")
+		})
+
+		test("continues after source error", async () => {
+			const failing: FeedSource = {
+				id: "failing",
+				...noActions,
+				async fetchContext() {
+					throw new Error("Failed")
+				},
+			}
+
+			const working: FeedSource = {
+				id: "working",
+				...noActions,
+				async fetchContext() {
+					return null
+				},
+				async fetchItems() {
+					return [
+						{
+							id: "item-1",
+							type: "test",
+							priority: 0.5,
+							timestamp: new Date(),
+							data: {},
+						},
+					]
+				},
+			}
+
+			const engine = new FeedEngine().register(failing).register(working)
+
+			const { items, errors } = await engine.refresh()
+
+			expect(errors).toHaveLength(1)
+			expect(items).toHaveLength(1)
+		})
+	})
+
+	describe("currentContext", () => {
+		test("returns initial context before refresh", () => {
+			const engine = new FeedEngine()
+
+			const context = engine.currentContext()
+
+			expect(context.time).toBeInstanceOf(Date)
+		})
+
+		test("returns accumulated context after refresh", async () => {
+			const location = createLocationSource()
+			location.simulateUpdate({ lat: 51.5, lng: -0.1 })
+
+			const engine = new FeedEngine().register(location)
+
+			await engine.refresh()
+
+			const context = engine.currentContext()
+			expect(context.get(LocationKey)).toEqual({
+				lat: 51.5,
+				lng: -0.1,
+			})
+		})
+	})
+
+	describe("subscribe", () => {
+		test("returns unsubscribe function", () => {
+			const engine = new FeedEngine()
+			let callCount = 0
+
+			const unsubscribe = engine.subscribe(() => {
+				callCount++
+			})
+
+			unsubscribe()
+
+			// Subscriber should not be called after unsubscribe
+			expect(callCount).toBe(0)
+		})
+	})
+
+	describe("reactive updates", () => {
+		test("start subscribes to onContextUpdate", async () => {
+			const location = createLocationSource()
+			const weather = createWeatherSource()
+
+			const engine = new FeedEngine().register(location).register(weather)
+
+			const results: Array<{ items: FeedItem[] }> = []
+			engine.subscribe((result) => {
+				results.push({ items: result.items })
+			})
+
+			engine.start()
+
+			// Simulate location update
+			location.simulateUpdate({ lat: 51.5, lng: -0.1 })
+
+			// Wait for async refresh
+			await new Promise((resolve) => setTimeout(resolve, 50))
+
+			expect(results.length).toBeGreaterThan(0)
+			expect(results[0]!.items[0]!.type).toBe("weather")
+		})
+
+		test("stop unsubscribes from all sources", async () => {
+			const location = createLocationSource()
+
+			const engine = new FeedEngine().register(location)
+
+			let callCount = 0
+			engine.subscribe(() => {
+				callCount++
+			})
+
+			engine.start()
+			engine.stop()
+
+			// Simulate update after stop
+			location.simulateUpdate({ lat: 1, lng: 1 })
+
+			await new Promise((resolve) => setTimeout(resolve, 50))
+
+			expect(callCount).toBe(0)
+		})
+
+		test("start is idempotent", () => {
+			const location = createLocationSource()
+			const engine = new FeedEngine().register(location)
+
+			// Should not throw or double-subscribe
+			engine.start()
+			engine.start()
+			engine.stop()
+		})
+	})
+
+	describe("executeAction", () => {
+		test("routes action to correct source", async () => {
+			let receivedAction = ""
+			let receivedParams: unknown = {}
+
+			const source: FeedSource = {
+				id: "test-source",
+				async listActions() {
+					return {
+						"do-thing": { id: "do-thing" },
+					}
+				},
+				async executeAction(actionId, params) {
+					receivedAction = actionId
+					receivedParams = params
+				},
+				async fetchContext() {
+					return null
+				},
+			}
+
+			const engine = new FeedEngine().register(source)
+			await engine.executeAction("test-source", "do-thing", { key: "value" })
+
+			expect(receivedAction).toBe("do-thing")
+			expect(receivedParams).toEqual({ key: "value" })
+		})
+
+		test("throws for unknown source", async () => {
+			const engine = new FeedEngine()
+
+			await expect(engine.executeAction("nonexistent", "action", {})).rejects.toThrow(
+				"Source not found: nonexistent",
+			)
+		})
+
+		test("throws for unknown action on source", async () => {
+			const source: FeedSource = {
+				id: "test-source",
+				...noActions,
+				async fetchContext() {
+					return null
+				},
+			}
+
+			const engine = new FeedEngine().register(source)
+
+			await expect(engine.executeAction("test-source", "nonexistent", {})).rejects.toThrow(
+				'Action "nonexistent" not found on source "test-source"',
+			)
+		})
+	})
+
+	describe("listActions", () => {
+		test("returns actions for a specific source", async () => {
+			const source: FeedSource = {
+				id: "test-source",
+				async listActions() {
+					return {
+						"action-1": { id: "action-1" },
+						"action-2": { id: "action-2" },
+					}
+				},
+				async executeAction() {},
+				async fetchContext() {
+					return null
+				},
+			}
+
+			const engine = new FeedEngine().register(source)
+			const actions = await engine.listActions("test-source")
+
+			expect(Object.keys(actions)).toEqual(["action-1", "action-2"])
+		})
+
+		test("throws for unknown source", async () => {
+			const engine = new FeedEngine()
+
+			await expect(engine.listActions("nonexistent")).rejects.toThrow(
+				"Source not found: nonexistent",
+			)
+		})
+
+		test("throws on mismatched action ID", async () => {
+			const source: FeedSource = {
+				id: "bad-source",
+				async listActions() {
+					return {
+						"correct-key": { id: "wrong-id" },
+					}
+				},
+				async executeAction() {},
+				async fetchContext() {
+					return null
+				},
+			}
+
+			const engine = new FeedEngine().register(source)
+
+			await expect(engine.listActions("bad-source")).rejects.toThrow(
+				'Action ID mismatch on source "bad-source"',
+			)
+		})
+	})
+
+	describe("lastFeed", () => {
+		test("returns null before any refresh", () => {
+			const engine = new FeedEngine()
+
+			expect(engine.lastFeed()).toBeNull()
+		})
+
+		test("returns cached result after refresh", async () => {
+			const location = createLocationSource()
+			location.simulateUpdate({ lat: 51.5, lng: -0.1 })
+
+			const weather = createWeatherSource()
+			const engine = new FeedEngine().register(location).register(weather)
+
+			const refreshResult = await engine.refresh()
+
+			const cached = engine.lastFeed()
+			expect(cached).not.toBeNull()
+			expect(cached!.items).toEqual(refreshResult.items)
+			expect(cached!.context).toEqual(refreshResult.context)
+		})
+
+		test("returns null after TTL expires", async () => {
+			const engine = new FeedEngine({ cacheTtlMs: 50 })
+			const location = createLocationSource()
+			location.simulateUpdate({ lat: 51.5, lng: -0.1 })
+
+			engine.register(location)
+			await engine.refresh()
+
+			expect(engine.lastFeed()).not.toBeNull()
+
+			await new Promise((resolve) => setTimeout(resolve, 60))
+
+			expect(engine.lastFeed()).toBeNull()
+		})
+
+		test("defaults to 5 minute TTL", async () => {
+			const engine = new FeedEngine()
+			const location = createLocationSource()
+			location.simulateUpdate({ lat: 51.5, lng: -0.1 })
+
+			engine.register(location)
+			await engine.refresh()
+
+			// Should still be cached immediately
+			expect(engine.lastFeed()).not.toBeNull()
+		})
+
+		test("refresh always fetches from sources", async () => {
+			let fetchCount = 0
+			const source: FeedSource = {
+				id: "counter",
+				...noActions,
+				async fetchContext() {
+					fetchCount++
+					return null
+				},
+			}
+
+			const engine = new FeedEngine().register(source)
+
+			await engine.refresh()
+			await engine.refresh()
+			await engine.refresh()
+
+			expect(fetchCount).toBe(3)
+		})
+
+		test("reactive context update refreshes cache", async () => {
+			const location = createLocationSource()
+			const weather = createWeatherSource()
+
+			const engine = new FeedEngine({ cacheTtlMs: 5000 }).register(location).register(weather)
+
+			engine.start()
+
+			// Simulate location update which triggers reactive refresh
+			location.simulateUpdate({ lat: 51.5, lng: -0.1 })
+
+			// Wait for async reactive refresh to complete
+			await new Promise((resolve) => setTimeout(resolve, 50))
+
+			const cached = engine.lastFeed()
+			expect(cached).not.toBeNull()
+			expect(cached!.items.length).toBeGreaterThan(0)
+
+			engine.stop()
+		})
+
+		test("reactive item update refreshes cache", async () => {
+			let itemUpdateCallback: ((items: FeedItem[]) => void) | null = null
+
+			const source: FeedSource = {
+				id: "reactive-items",
+				...noActions,
+				async fetchContext() {
+					return null
+				},
+				async fetchItems() {
+					return [
+						{
+							id: "item-1",
+							type: "test",
+							priority: 0.5,
+							timestamp: new Date(),
+							data: {},
+						},
+					]
+				},
+				onItemsUpdate(callback) {
+					itemUpdateCallback = callback
+					return () => {
+						itemUpdateCallback = null
+					}
+				},
+			}
+
+			const engine = new FeedEngine().register(source)
+			engine.start()
+
+			// Trigger item update
+			itemUpdateCallback!([])
+
+			// Wait for async refresh
+			await new Promise((resolve) => setTimeout(resolve, 50))
+
+			const cached = engine.lastFeed()
+			expect(cached).not.toBeNull()
+			expect(cached!.items).toHaveLength(1)
+
+			engine.stop()
+		})
+
+		test("TTL resets after reactive update", async () => {
+			const location = createLocationSource()
+			const weather = createWeatherSource()
+
+			const engine = new FeedEngine({ cacheTtlMs: 100 }).register(location).register(weather)
+
+			engine.start()
+
+			// Initial reactive update
+			location.simulateUpdate({ lat: 51.5, lng: -0.1 })
+			await new Promise((resolve) => setTimeout(resolve, 50))
+
+			expect(engine.lastFeed()).not.toBeNull()
+
+			// Wait 70ms (total 120ms from first update, past original TTL)
+			// but trigger another update at 50ms to reset TTL
+			location.simulateUpdate({ lat: 52.0, lng: -0.2 })
+			await new Promise((resolve) => setTimeout(resolve, 50))
+
+			// Should still be cached because TTL was reset by second update
+			expect(engine.lastFeed()).not.toBeNull()
+
+			engine.stop()
+		})
+
+		test("cacheTtlMs is configurable", async () => {
+			const engine = new FeedEngine({ cacheTtlMs: 30 })
+			const location = createLocationSource()
+			location.simulateUpdate({ lat: 51.5, lng: -0.1 })
+
+			engine.register(location)
+			await engine.refresh()
+
+			expect(engine.lastFeed()).not.toBeNull()
+
+			await new Promise((resolve) => setTimeout(resolve, 40))
+
+			expect(engine.lastFeed()).toBeNull()
+		})
+
+		test("auto-refreshes on TTL interval after start", async () => {
+			let fetchCount = 0
+			const source: FeedSource = {
+				id: "counter",
+				...noActions,
+				async fetchContext() {
+					fetchCount++
+					return null
+				},
+				async fetchItems() {
+					return [
+						{
+							id: `item-${fetchCount}`,
+							type: "test",
+							priority: 0.5,
+							timestamp: new Date(),
+							data: {},
+						},
+					]
+				},
+			}
+
+			const engine = new FeedEngine({ cacheTtlMs: 50 }).register(source)
+			engine.start()
+
+			// Wait for two TTL intervals to elapse
+			await new Promise((resolve) => setTimeout(resolve, 120))
+
+			// Should have auto-refreshed at least twice
+			expect(fetchCount).toBeGreaterThanOrEqual(2)
+			expect(engine.lastFeed()).not.toBeNull()
+
+			engine.stop()
+		})
+
+		test("stop cancels periodic refresh", async () => {
+			let fetchCount = 0
+			const source: FeedSource = {
+				id: "counter",
+				...noActions,
+				async fetchContext() {
+					fetchCount++
+					return null
+				},
+			}
+
+			const engine = new FeedEngine({ cacheTtlMs: 50 }).register(source)
+			engine.start()
+			engine.stop()
+
+			const countAfterStop = fetchCount
+
+			// Wait past TTL
+			await new Promise((resolve) => setTimeout(resolve, 80))
+
+			// No additional fetches after stop
+			expect(fetchCount).toBe(countAfterStop)
+		})
+
+		test("reactive update resets periodic refresh timer", async () => {
+			let fetchCount = 0
+			const location = createLocationSource()
+			const countingWeather: FeedSource<WeatherFeedItem> = {
+				id: "weather",
+				dependencies: ["location"],
+				...noActions,
+				async fetchContext(ctx) {
+					fetchCount++
+					const loc = ctx.get(LocationKey)
+					if (!loc) return null
+					return [[WeatherKey, { temperature: 20, condition: "sunny" }]]
+				},
+				async fetchItems(ctx) {
+					const weather = ctx.get(WeatherKey)
+					if (!weather) return []
+					return [
+						{
+							id: `weather-${Date.now()}`,
+							type: "weather",
+							priority: 0.5,
+							timestamp: new Date(),
+							data: { temperature: weather.temperature, condition: weather.condition },
+						},
+					]
+				},
+			}
+
+			const engine = new FeedEngine({ cacheTtlMs: 100 })
+				.register(location)
+				.register(countingWeather)
+
+			engine.start()
+
+			// At 40ms, push a reactive update — this resets the timer
+			await new Promise((resolve) => setTimeout(resolve, 40))
+			const countBeforeUpdate = fetchCount
+			location.simulateUpdate({ lat: 51.5, lng: -0.1 })
+			await new Promise((resolve) => setTimeout(resolve, 20))
+
+			// Reactive update triggered a fetch
+			expect(fetchCount).toBeGreaterThan(countBeforeUpdate)
+			const countAfterUpdate = fetchCount
+
+			// At 100ms from start (60ms after reactive update), the original
+			// timer would have fired, but it was reset. No extra fetch yet.
+			await new Promise((resolve) => setTimeout(resolve, 40))
+			expect(fetchCount).toBe(countAfterUpdate)
+
+			engine.stop()
+		})
+	})
+})