fix: caches work on unknown data types

the previous generic typing caused a situation where a single cache instance
could not be reused on different cachified calls operating on varying data types

This was never a design goal and happened as a over-optimization when implementing against
tests instead of a rl-app 😅

fix: #5

BREAKING CHANGE:
The `Cache` type is not generic anymore and always uses `unknown` for values
You might need to adjust your cache implementations and caches to now work on
unknown data types. Typescript should inform you where.
Nothing to be done when you only used the build-in cache adapters.

Author: Xiphe

src/adapters.ts

@@ -1,16 +1,14 @@
 import { Cache, CacheEntry } from './common';
 
-export interface LRUishCache<Value> extends Omit<Cache<Value>, 'set'> {
+export interface LRUishCache extends Omit<Cache, 'set'> {
   set(
     key: string,
-    value: CacheEntry<Value>,
+    value: CacheEntry<unknown>,
     options?: { ttl?: number; start?: number },
   ): void;
 }
 
-export function lruCacheAdapter<Value>(
-  lruCache: LRUishCache<Value>,
-): Cache<Value> {
+export function lruCacheAdapter(lruCache: LRUishCache): Cache {
   return {
     name: lruCache.name || 'LRU',
     set(key, value) {
@@ -50,9 +48,7 @@ export interface Redis3LikeCache {
   multi(): Redis3Multi;
 }
 
-export function redis3CacheAdapter<Value>(
-  redisCache: Redis3LikeCache,
-): Cache<Value> {
+export function redis3CacheAdapter(redisCache: Redis3LikeCache): Cache {
   return {
     name: redisCache.name || 'Redis3',
     set(key, value) {
@@ -78,7 +74,7 @@ export function redis3CacheAdapter<Value>(
       });
     },
     get(key) {
-      return new Promise<CacheEntry<Value> | null | undefined>((res, rej) => {
+      return new Promise<CacheEntry | null | undefined>((res, rej) => {
         redisCache.get(key, (err, reply) => {
           if (err) {
             rej(err);
@@ -118,9 +114,7 @@ export interface RedisLikeCache {
   del(key: string): Promise<unknown>;
 }
 
-export function redisCacheAdapter<Value>(
-  redisCache: RedisLikeCache,
-): Cache<Value> {
+export function redisCacheAdapter(redisCache: RedisLikeCache): Cache {
   return {
     name: redisCache.name || 'Redis',
     set(key, value) {

src/cachified.spec.ts

@@ -35,7 +35,7 @@ beforeEach(() => {
 
 describe('cachified', () => {
   it('caches a value', async () => {
-    const cache = new Map<string, CacheEntry<string>>();
+    const cache = new Map<string, CacheEntry>();
     const reporter = createReporter();
     const reporter2 = createReporter();
 
@@ -84,7 +84,7 @@ describe('cachified', () => {
   });
 
   it('immediately refreshes when ttl is 0', async () => {
-    const cache = new Map<string, CacheEntry<string>>();
+    const cache = new Map<string, CacheEntry>();
 
     const value = await cachified({
       cache,
@@ -110,7 +110,7 @@ describe('cachified', () => {
   });
 
   it('caches undefined values', async () => {
-    const cache = new Map<string, CacheEntry<undefined>>();
+    const cache = new Map<string, CacheEntry>();
 
     const value = await cachified({
       cache,
@@ -133,7 +133,7 @@ describe('cachified', () => {
   });
 
   it('caches null values', async () => {
-    const cache = new Map<string, CacheEntry<null>>();
+    const cache = new Map<string, CacheEntry>();
 
     const value = await cachified({
       cache,
@@ -156,7 +156,7 @@ describe('cachified', () => {
   });
 
   it('throws when no fresh value can be received for empty cache', async () => {
-    const cache = new Map<string, CacheEntry<string>>();
+    const cache = new Map<string, CacheEntry>();
     const reporter = createReporter();
 
     const value = cachified({
@@ -182,7 +182,7 @@ describe('cachified', () => {
   });
 
   it('throws when no forced fresh value can be received on empty cache', async () => {
-    const cache = new Map<string, CacheEntry<string>>();
+    const cache = new Map<string, CacheEntry>();
 
     const value = cachified({
       cache,
@@ -197,7 +197,7 @@ describe('cachified', () => {
   });
 
   it('throws when fresh value does not meet value check', async () => {
-    const cache = new Map<string, CacheEntry<string>>();
+    const cache = new Map<string, CacheEntry>();
     const reporter = createReporter();
     const reporter2 = createReporter();
 
@@ -259,7 +259,7 @@ describe('cachified', () => {
   });
 
   it('supports migrating cached values', async () => {
-    const cache = new Map<string, CacheEntry<string>>();
+    const cache = new Map<string, CacheEntry>();
     const reporter = createReporter();
 
     cache.set('weather', createCacheEntry('☁️'));
@@ -292,7 +292,7 @@ describe('cachified', () => {
   });
 
   it('supports async value checkers that throw', async () => {
-    const cache = new Map<string, CacheEntry<string>>();
+    const cache = new Map<string, CacheEntry>();
     const reporter = createReporter();
 
     const value = cachified({
@@ -347,7 +347,7 @@ describe('cachified', () => {
   });
 
   it('does not write migrated value to cache in case a new fresh value is already incoming', async () => {
-    const cache = new Map<string, CacheEntry<string>>();
+    const cache = new Map<string, CacheEntry>();
     const reporter = createReporter();
 
     cache.set('weather', createCacheEntry('☁️'));
@@ -389,7 +389,7 @@ describe('cachified', () => {
   });
 
   it('gets different values for different keys', async () => {
-    const cache = new Map<string, CacheEntry<string>>();
+    const cache = new Map<string, CacheEntry>();
 
     const value = await cachified({
       cache,
@@ -422,7 +422,7 @@ describe('cachified', () => {
   });
 
   it('gets fresh value when forced to', async () => {
-    const cache = new Map<string, CacheEntry<string>>();
+    const cache = new Map<string, CacheEntry>();
 
     const value = await cachified({
       cache,
@@ -445,7 +445,7 @@ describe('cachified', () => {
   });
 
   it('falls back to cache when forced fresh value fails', async () => {
-    const cache = new Map<string, CacheEntry<string>>();
+    const cache = new Map<string, CacheEntry>();
     const reporter = createReporter();
 
     cache.set('test', createCacheEntry('ONE'));
@@ -477,7 +477,7 @@ describe('cachified', () => {
   });
 
   it('does not fall back to outdated cache', async () => {
-    const cache = new Map<string, CacheEntry<string>>();
+    const cache = new Map<string, CacheEntry>();
     const reporter = createReporter();
 
     cache.set('test', createCacheEntry('ONE', { ttl: 5 }));
@@ -497,7 +497,7 @@ describe('cachified', () => {
   });
 
   it('it throws when cache fallback is disabled and getting fresh value fails', async () => {
-    const cache = new Map<string, CacheEntry<string>>();
+    const cache = new Map<string, CacheEntry>();
 
     const value1 = await cachified({
       cache,
@@ -519,7 +519,7 @@ describe('cachified', () => {
   });
 
   it('handles cache write fails', async () => {
-    const cache = new Map<string, CacheEntry<string>>();
+    const cache = new Map<string, CacheEntry>();
     const setMock = jest.spyOn(cache, 'set');
     const reporter = createReporter();
     let i = 0;
@@ -562,7 +562,7 @@ describe('cachified', () => {
   });
 
   it('gets fresh value when ttl is exceeded', async () => {
-    const cache = new Map<string, CacheEntry<string>>();
+    const cache = new Map<string, CacheEntry>();
     const reporter = createReporter();
     let i = 0;
     const getValue = () =>
@@ -617,7 +617,7 @@ describe('cachified', () => {
   });
 
   it('does not write to cache when ttl is exceeded before value is received', async () => {
-    const cache = new Map<string, CacheEntry<string>>();
+    const cache = new Map<string, CacheEntry>();
     const setMock = jest.spyOn(cache, 'set');
     const reporter = createReporter();
 
@@ -649,7 +649,7 @@ describe('cachified', () => {
   });
 
   it('reuses pending fresh value for parallel calls', async () => {
-    const cache = new Map<string, CacheEntry<string>>();
+    const cache = new Map<string, CacheEntry>();
     const reporter = createReporter();
     const getValue = (
       getFreshValue: CachifiedOptions<string>['getFreshValue'],
@@ -691,7 +691,7 @@ describe('cachified', () => {
   });
 
   it('resolves earlier pending values with faster responses from later calls', async () => {
-    const cache = new Map<string, CacheEntry<string>>();
+    const cache = new Map<string, CacheEntry>();
     const getValue = (
       getFreshValue: CachifiedOptions<string>['getFreshValue'],
     ) =>
@@ -726,7 +726,7 @@ describe('cachified', () => {
   });
 
   it('uses stale cache while revalidating', async () => {
-    const cache = new Map<string, CacheEntry<string>>();
+    const cache = new Map<string, CacheEntry>();
     const reporter = createReporter();
     let i = 0;
     const getFreshValue = jest.fn(() => `value-${i++}`);
@@ -783,7 +783,7 @@ describe('cachified', () => {
   });
 
   it('supports infinite stale while revalidate', async () => {
-    const cache = new Map<string, CacheEntry<string>>();
+    const cache = new Map<string, CacheEntry>();
     let i = 0;
     const getFreshValue = jest.fn(() => `value-${i++}`);
     const getValue = () =>
@@ -811,7 +811,7 @@ describe('cachified', () => {
   });
 
   it('ignores errors when revalidating cache in the background', async () => {
-    const cache = new Map<string, CacheEntry<string>>();
+    const cache = new Map<string, CacheEntry>();
     const reporter = createReporter();
     let i = 0;
     const getFreshValue = jest.fn(() => `value-${i++}`);
@@ -867,7 +867,7 @@ describe('cachified', () => {
   });
 
   it('gets fresh value in case cached one does not meet value check', async () => {
-    const cache = new Map<string, CacheEntry<string>>();
+    const cache = new Map<string, CacheEntry>();
     const reporter = createReporter();
     const reporter2 = createReporter();
 
@@ -931,7 +931,7 @@ describe('cachified', () => {
   });
 
   it('supports batch-getting fresh values', async () => {
-    const cache = new Map<string, CacheEntry<string>>();
+    const cache = new Map<string, CacheEntry>();
     cache.set('test-2', createCacheEntry('YOLO!', { swv: null }));
     const getValues = jest.fn((indexes: number[]) =>
       indexes.map((i) => `value-${i}`),
@@ -961,7 +961,7 @@ describe('cachified', () => {
   });
 
   it('rejects all values when batch get fails', async () => {
-    const cache = new Map<string, CacheEntry<string>>();
+    const cache = new Map<string, CacheEntry>();
 
     const batch = createBatch<string, any>(() => {
       throw new Error('🥊');
@@ -981,7 +981,7 @@ describe('cachified', () => {
   });
 
   it('supports manual submission of batch', async () => {
-    const cache = new Map<string, CacheEntry<string>>();
+    const cache = new Map<string, CacheEntry>();
     const getValues = jest.fn((indexes: (number | string)[]) =>
       indexes.map((i) => `value-${i}`),
     );
@@ -1075,7 +1075,7 @@ describe('cachified', () => {
   });
 
   it('works with LRU cache', async () => {
-    const lru = new LRUCache<string, CacheEntry<string>>({ max: 5 });
+    const lru = new LRUCache<string, CacheEntry>({ max: 5 });
     const cache = lruCacheAdapter(lru);
 
     const value = await cachified({
@@ -1265,7 +1265,7 @@ describe('cachified', () => {
 
 describe('verbose reporter', () => {
   it('logs when cached value is invalid', async () => {
-    const cache = new Map<string, CacheEntry<string>>();
+    const cache = new Map<string, CacheEntry>();
     const logger = createLogger();
     cache.set('test', createCacheEntry('One'));
 
@@ -1286,7 +1286,7 @@ describe('verbose reporter', () => {
   });
 
   it('logs when getting a cached value fails', async () => {
-    const cache = new Map<string, CacheEntry<string>>();
+    const cache = new Map<string, CacheEntry>();
     const logger = createLogger();
     const getMock = jest.spyOn(cache, 'get');
     getMock.mockImplementationOnce(() => {
@@ -1309,7 +1309,7 @@ describe('verbose reporter', () => {
   });
 
   it('logs when getting a fresh value fails', async () => {
-    const cache = new Map<string, CacheEntry<string>>();
+    const cache = new Map<string, CacheEntry>();
     const logger = createLogger();
 
     await cachified({
@@ -1329,7 +1329,7 @@ describe('verbose reporter', () => {
   });
 
   it('logs when fresh value is not written to cache', async () => {
-    const cache = new Map<string, CacheEntry<string>>();
+    const cache = new Map<string, CacheEntry>();
     const logger = createLogger();
 
     await cachified({
@@ -1350,7 +1350,7 @@ describe('verbose reporter', () => {
   });
 
   it('logs when writing to cache fails (using defaults)', async () => {
-    const cache = new Map<string, CacheEntry<string>>();
+    const cache = new Map<string, CacheEntry>();
     const errorMock = jest.spyOn(console, 'error').mockImplementation(() => {
       /* 🤫 */
     });
@@ -1378,7 +1378,7 @@ describe('verbose reporter', () => {
   it('falls back to Date when performance is not globally available', async () => {
     const backup = global.performance;
     delete (global as any).performance;
-    const cache = new Map<string, CacheEntry<string>>();
+    const cache = new Map<string, CacheEntry>();
     const logger = createLogger();
 
     await cachified({
@@ -1393,7 +1393,7 @@ describe('verbose reporter', () => {
   });
 
   it('logs when fresh value does not meet value check', async () => {
-    const cache = new Map<string, CacheEntry<string>>();
+    const cache = new Map<string, CacheEntry>();
     const logger = createLogger();
 
     await cachified({
@@ -1413,7 +1413,7 @@ describe('verbose reporter', () => {
   });
 
   it('logs when cache is successfully revalidated', async () => {
-    const cache = new Map<string, CacheEntry<string>>();
+    const cache = new Map<string, CacheEntry>();
     const logger = createLogger();
     cache.set('test', createCacheEntry('ONE', { ttl: 5, swv: 10 }));
     currentTime = 7;
@@ -1435,7 +1435,7 @@ describe('verbose reporter', () => {
   });
 
   it('logs when cache revalidation fails', async () => {
-    const cache = new Map<string, CacheEntry<string>>();
+    const cache = new Map<string, CacheEntry>();
     const logger = createLogger();
     cache.set('test', createCacheEntry('ONE', { ttl: 5, swv: 10 }));
     currentTime = 7;

src/cachified.ts

@@ -6,7 +6,7 @@ import { shouldRefresh } from './shouldRefresh';
 // This is to prevent requesting multiple fresh values in parallel
 // while revalidating or getting first value
 // Keys are unique per cache but may be used by multiple caches
-const pendingValuesByCache = new WeakMap<Cache<any>, Map<string, any>>();
+const pendingValuesByCache = new WeakMap<Cache, Map<string, any>>();
 
 export async function cachified<Value>(
   options: CachifiedOptions<Value>,