feat: support sync cache creation (#598)

* feat: support sync cache creation
Add non-async `createCache()` that `caching()` uses to set up methods.

* Update readme with `createCache()`

* Update test.yml

---------

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

.github/workflows/test.yml

@@ -13,7 +13,7 @@ jobs:
 
     strategy:
       matrix:
-        node-version: ['16', '18', '20']
+        node-version: ['18', '20']
 
     steps:
       - uses: actions/checkout@v3

README.md

@@ -84,6 +84,32 @@ You can use your own custom store by creating one with the same API as the built
 - [Example Custom Store redis](https://github.com/node-cache-manager/node-cache-manager-redis-yet)
 - [Example Custom Store ioredis](https://github.com/node-cache-manager/node-cache-manager-ioredis-yet)
 
+#### Create single cache store synchronously
+
+As `caching()` requires async functionality to resolve some stores, this is not well-suited to use for default function/constructor parameters etc.
+
+If you need to create a cache store synchronously, you can instead use `createCache()`:
+
+```typescript
+import { createCache, memoryStore } from 'node-cache-manager';
+
+// Create memory cache synchronously
+const memoryCache = createCache(memoryStore(), {
+  max: 100,
+  ttl: 10 * 1000 /*milliseconds*/,
+});
+
+// Default parameter in function
+function myService(cache = createCache(memoryStore())) {}
+
+// Default parameter in class constructor
+const DEFAULT_CACHE = createCache(memoryStore(), { ttl: 60 * 1000 });
+// ...
+class MyService {
+  constructor(private cache = DEFAULT_CACHE) {}
+}
+```
+
 ### Multi-Store
 
 ```typescript

src/caching.ts

@@ -1,5 +1,5 @@
 import { coalesceAsync } from 'promise-coalesce';
-import { MemoryCache, MemoryConfig, memoryStore } from './stores';
+import { MemoryCache, MemoryConfig, MemoryStore, memoryStore } from './stores';
 
 export type Config = {
   ttl?: Milliseconds;
@@ -63,13 +63,34 @@ export async function caching<S extends Store, T extends object = never>(
 export async function caching<S extends Store, T extends object = never>(
   factory: Stores<S, T>,
   args?: CachingConfig<T>,
-): Promise<Cache<S> | MemoryCache> {
-  let store: Store;
-  if (factory === 'memory') store = memoryStore(args as MemoryConfig);
-  else if (typeof factory === 'function')
-    store = await factory(args as FactoryConfig<T>);
-  else store = factory;
+): Promise<Cache<S> | Cache<Store> | MemoryCache> {
+  if (factory === 'memory') {
+    const store = memoryStore(args as MemoryConfig);
+    return createCache(store, args as MemoryConfig);
+  }
+  if (typeof factory === 'function') {
+    const store = await factory(args as FactoryConfig<T>);
+    return createCache(store, args);
+  }
 
+  const store = factory;
+  return createCache(store, args);
+}
+
+export function createCache(
+  store: MemoryStore,
+  args?: MemoryConfig,
+): MemoryCache;
+
+export function createCache(store: Store, args?: Config): Cache<Store>;
+
+/**
+ * Create cache instance by store (non-async).
+ */
+export function createCache<S extends Store, C extends Config>(
+  store: S,
+  args?: C,
+): Cache<S> {
   return {
     /**
      * Wraps a function in cache. I.e., the first time the function is run,

test/caching.test.ts

@@ -2,7 +2,7 @@ import { faker } from '@faker-js/faker';
 import promiseCoalesce from 'promise-coalesce';
 import { beforeEach, describe, expect, it, vi } from 'vitest';
 
-import { Cache, MemoryConfig, caching, memoryStore } from '../src';
+import { caching, Cache, MemoryConfig, memoryStore, createCache } from '../src';
 import { sleep } from './utils';
 
 // Allow the module to be mocked so we can assert
@@ -389,3 +389,15 @@ describe('caching', () => {
     });
   });
 });
+
+describe('createCache', () => {
+  it('should create cache instance by store', async () => {
+    const store = memoryStore();
+    const cache1 = await caching(store);
+    const cache2 = createCache(store);
+    expect(cache1.store).toBe(cache2.store);
+    Object.entries(cache1).forEach(([key, value]) => {
+      expect(cache2[key as keyof Cache].toString()).toBe(value.toString());
+    });
+  });
+});