fix: re populate higher priority caches when a key is found in lower …

…ones
jaredwray · Nov 2, 2022 · 7a6a10c · 7a6a10c
1 parent e1e7e8b
commit 7a6a10c
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Showing 2 changed files with 42 additions and 6 deletions.
diff --git a/src/multi-caching.ts b/src/multi-caching.ts
@@ -25,12 +25,23 @@ export function multiCaching<Caches extends Cache[]>(
     del: async (key) => {
       await Promise.all(caches.map((cache) => cache.del(key)));
     },
-    async wrap<T>(key: string, fn: () => Promise<T>): Promise<T> {
-      const value = await get<T>(key);
+    async wrap<T>(key: string, fn: () => Promise<T>, ttl?: Ttl): Promise<T> {
+      let value: T | undefined;
+      let i = 0;
+      for (; i < caches.length; i++) {
+        try {
+          value = await caches[i].get<T>(key);
+          if (value !== undefined) break;
+        } catch (e) {}
+      }
       if (value === undefined) {
         const result = await fn();
-        await set<T>(key, result);
+        await set<T>(key, result, ttl);
         return result;
+      } else {
+        for (let j = 0; j < i; j++) {
+          await caches[j].set(key, value, ttl);
+        }
       }
       return value;
     },

diff --git a/test/multi-caching.test.ts b/test/multi-caching.test.ts
@@ -1,4 +1,8 @@
 import { describe, expect, it, beforeEach } from 'vitest';
+import { faker } from '@faker-js/faker';
+
+import { sleep } from './utils';
+
 import {
   Cache,
   caching,
@@ -7,9 +11,8 @@ import {
   multiCaching,
   Store,
 } from '../src';
-import { faker } from '@faker-js/faker';
 
-describe('multiCaching', function () {
+describe('multiCaching', () => {
   let memoryCache: MemoryCache;
   let memoryCache2: MemoryCache;
   let memoryCache3: MemoryCache;
@@ -38,7 +41,7 @@ describe('multiCaching', function () {
   describe('get(), set(), del(), reset(), mget(), mset()', () => {
     let value: string;
 
-    beforeEach(function () {
+    beforeEach(() => {
       multiCache = multiCaching([memoryCache, memoryCache2, memoryCache3]);
       key = faker.datatype.string(20);
       value = faker.datatype.string();
@@ -136,4 +139,26 @@ describe('multiCaching', function () {
       });
     });
   });
+
+  describe('issues', () => {
+    it('#253', async () => {
+      const cache0 = await caching('memory', { ttl: 100 });
+      const cache1 = await caching('memory', { ttl: 1000 });
+      const multi = multiCaching([cache0, cache1]);
+      const key = 'bar';
+      const value = 'foo';
+
+      const fn = async () => value;
+
+      await multi.wrap(key, fn);
+      await sleep(100);
+      await expect(cache0.get(key)).resolves.toBeUndefined();
+      await expect(cache1.get(key)).resolves.toEqual(value);
+
+      await multi.wrap(key, fn);
+
+      await expect(cache0.get(key)).resolves.toEqual(value);
+      await expect(cache1.get(key)).resolves.toEqual(value);
+    });
+  });
 });