cache-manager - feat: add store layer identification to event payloads (#1270)

* feat(cache-manager): add store layer identification to event payloads (#1128)

* adding in biome ignore on tests files

---------

Co-authored-by: Jared Wray <me@jaredwray.com>

Author: faizanu94

packages/cache-manager/src/index.ts

@@ -5,6 +5,8 @@ import { isObject } from "./is-object.js";
 import { lt } from "./lt.js";
 import { runIfFn } from "./run-if-fn.js";
 
+const _storeLabel = (i: number) => (i === 0 ? "primary" : `secondary:${i - 1}`);
+
 export type CreateCacheOptions = {
 	stores?: Keyv[];
 	ttl?: number;
@@ -105,16 +107,21 @@ export const createCache = (options?: CreateCacheOptions): Cache => {
 				eventEmitter.emit("get", { key, error });
 			}
 		} else {
-			for (const store of stores) {
+			for (let i = 0; i < stores.length; i++) {
+				const store = stores[i];
 				try {
 					const cacheValue = await store.get<T>(key);
 					if (cacheValue !== undefined) {
 						result = cacheValue;
-						eventEmitter.emit("get", { key, value: result });
+						eventEmitter.emit("get", {
+							key,
+							value: result,
+							store: _storeLabel(i),
+						});
 						break;
 					}
 				} catch (error) {
-					eventEmitter.emit("get", { key, error });
+					eventEmitter.emit("get", { key, error, store: _storeLabel(i) });
 				}
 			}
 		}
@@ -212,19 +219,18 @@ export const createCache = (options?: CreateCacheOptions): Cache => {
 		ttl?: number,
 	): Promise<T> => {
 		try {
+			const promises = stores.map(async (store, i) => {
+				await store.set(key, value, ttl ?? options?.ttl);
+				eventEmitter.emit("set", { key, value, store: _storeLabel(i) });
+			});
+
 			if (nonBlocking) {
-				Promise.all(
-					stores.map(async (store) =>
-						store.set(key, value, ttl ?? options?.ttl),
-					),
-				);
+				Promise.all(promises);
 				eventEmitter.emit("set", { key, value });
 				return value;
 			}
 
-			await Promise.all(
-				stores.map(async (store) => store.set(key, value, ttl ?? options?.ttl)),
-			);
+			await Promise.all(promises);
 			eventEmitter.emit("set", { key, value });
 			return value;
 		} catch (error) {

packages/cache-manager/test/events.test.ts

@@ -1,3 +1,4 @@
+// biome-ignore-all lint/suspicious/noExplicitAny: test file
 import { faker } from "@faker-js/faker";
 import { Keyv } from "keyv";
 import { beforeEach, describe, expect, it, vi } from "vitest";
@@ -132,4 +133,44 @@ describe("events", () => {
 			error,
 		});
 	});
+
+	it("event: get includes store and value", async () => {
+		const listener = vi.fn();
+
+		cache.on("get", listener);
+
+		await cache.set(data.key, data.value);
+		await cache.get(data.key);
+
+		expect(listener).toHaveBeenCalled();
+
+		const payload = listener.mock.calls[0][0];
+
+		expect(payload).toMatchObject({
+			key: data.key,
+			value: data.value,
+			store: "primary",
+		});
+	});
+
+	it("event: get error includes store", async () => {
+		const l1 = new Keyv();
+		const l2 = new Keyv();
+
+		const cache = createCache({ stores: [l1, l2] });
+		const events: any[] = [];
+
+		cache.on("get", (e: any) => events.push(e));
+
+		l1.get = () => {
+			throw new Error("boom");
+		};
+
+		await expect(cache.get("nope")).resolves.toBeUndefined();
+
+		const errEvt = events.find((e) => e.error);
+
+		expect(errEvt).toBeTruthy();
+		expect(errEvt.store).toBe("primary");
+	});
 });

packages/cache-manager/test/multiple-stores.test.ts

@@ -1,3 +1,4 @@
+// biome-ignore-all lint/suspicious/noExplicitAny: test file
 import { faker } from "@faker-js/faker";
 import { Keyv } from "keyv";
 import { beforeEach, describe, expect, it, vi } from "vitest";
@@ -111,4 +112,52 @@ describe("multiple stores", () => {
 			"new",
 		);
 	});
+
+	it("event: get emits store id for secondary hit", async () => {
+		const events: any[] = [];
+
+		cache.on("get", (e: any) => events.push(e));
+
+		await keyv2.set(data.key, data.value);
+		await expect(cache.get(data.key)).resolves.toEqual(data.value);
+
+		const rec = events.find((e) => e.key === data.key);
+
+		expect(rec).toBeTruthy();
+		expect(typeof rec.store).toBe("string");
+		expect(rec.store).not.toBe("primary");
+	});
+
+	it("event: set emits store id per layer (primary + secondary)", async () => {
+		const events: any[] = [];
+
+		cache.on("set", (e: any) => events.push(e));
+
+		await cache.set(data.key, data.value, ttl);
+
+		const stores = events.filter((e) => e.key === data.key).map((e) => e.store);
+
+		expect(stores.length).toBeGreaterThanOrEqual(2);
+		expect(new Set(stores).size).toBeGreaterThanOrEqual(2);
+		expect(stores).toContain("primary");
+		expect(stores).toContain("secondary:0");
+	});
+
+	it("event: get includes store for deeper layers (secondary:1)", async () => {
+		const l1 = new Keyv();
+		const l2 = new Keyv();
+		const l3 = new Keyv();
+
+		const cache = createCache({ stores: [l1, l2, l3] });
+
+		const events: any[] = [];
+		cache.on("get", (e: any) => events.push(e));
+
+		await l3.set(data.key, data.value);
+		await expect(cache.get(data.key)).resolves.toEqual(data.value);
+
+		const rec = events.find((e) => e.key === data.key);
+
+		expect(rec.store).toBe("secondary:1");
+	});
 });