feat(cache): improved customizability

deno_dist/middleware/cache/index.ts

@@ -2,10 +2,11 @@ import type { Context } from '../../context.ts'
 import type { MiddlewareHandler } from '../../types.ts'
 
 export const cache = (options: {
-  cacheName: string
+  cacheName: string | ((c: Context) => Promise<string> | string)
   wait?: boolean
   cacheControl?: string
   vary?: string | string[]
+  keyGenerator?: (c: Context) => Promise<string> | string
 }): MiddlewareHandler => {
   if (!globalThis.caches) {
     console.log('Cache Middleware is not enabled because caches is not defined.')
@@ -68,8 +69,14 @@ export const cache = (options: {
   }
 
   return async function cache(c, next) {
-    const key = c.req.url
-    const cache = await caches.open(options.cacheName)
+    let key = c.req.url
+    if (options.keyGenerator) {
+      key = await options.keyGenerator(c)
+    }
+
+    const cacheName =
+      typeof options.cacheName === 'function' ? await options.cacheName(c) : options.cacheName
+    const cache = await caches.open(cacheName)
     const response = await cache.match(key)
     if (response) {
       return new Response(response.body, response)

src/middleware/cache/index.test.ts

@@ -11,6 +11,73 @@ class Context implements ExecutionContext {
   }
 }
 
+describe('Customizing Caching Keys', () => {
+  const app = new Hono()
+
+  const dynamicCacheName = 'dynamic-cache-name'
+  app.use(
+    '/dynamic-cache-name/*',
+    cache({
+      cacheName: async () => dynamicCacheName,
+      wait: true,
+      cacheControl: 'max-age=10',
+    })
+  )
+  app.get('/dynamic-cache-name/', (c) => {
+    return c.text('cached')
+  })
+
+  const dynamicCacheKey = 'dynamic-cache-key'
+  app.use(
+    '/dynamic-cache-key/*',
+    cache({
+      cacheName: 'my-app-v1',
+      wait: true,
+      cacheControl: 'max-age=10',
+      keyGenerator: async () => dynamicCacheKey,
+    })
+  )
+  app.get('/dynamic-cache-key/', (c) => {
+    return c.text('cached')
+  })
+
+  app.use(
+    '/dynamic-cache/*',
+    cache({
+      cacheName: async () => dynamicCacheName,
+      cacheControl: 'max-age=10',
+      keyGenerator: async () => dynamicCacheKey,
+    })
+  )
+  app.get('/dynamic-cache/', (c) => {
+    return c.text('cached')
+  })
+
+  const ctx = new Context()
+
+  it('Should use dynamically generated cache name', async () => {
+    await app.request('http://localhost/dynamic-cache-name/', undefined, ctx)
+    const cache = await caches.open(dynamicCacheName)
+    const keys = Array.from(await cache.keys())
+    expect(keys.length).toBe(1)
+  })
+
+  it('Should use dynamically generated cache key', async () => {
+    await app.request('http://localhost/dynamic-cache-key/')
+    const cache = await caches.open('my-app-v1')
+    const response = await cache.match(dynamicCacheKey)
+    expect(response).not.toBeNull()
+  })
+
+  it('Should retrieve cached response with dynamic cache name and key', async () => {
+    await app.request('http://localhost/dynamic-cache/', undefined, undefined, ctx)
+    const res = await app.request('http://localhost/dynamic-cache/', undefined, undefined, ctx)
+    expect(res).not.toBeNull()
+    expect(res.status).toBe(200)
+    expect(res.headers.get('cache-control')).toBe('max-age=10')
+  })
+})
+
 describe('Cache Middleware', () => {
   const app = new Hono()
 

src/middleware/cache/index.ts

@@ -2,10 +2,11 @@ import type { Context } from '../../context'
 import type { MiddlewareHandler } from '../../types'
 
 export const cache = (options: {
-  cacheName: string
+  cacheName: string | ((c: Context) => Promise<string> | string)
   wait?: boolean
   cacheControl?: string
   vary?: string | string[]
+  keyGenerator?: (c: Context) => Promise<string> | string
 }): MiddlewareHandler => {
   if (!globalThis.caches) {
     console.log('Cache Middleware is not enabled because caches is not defined.')
@@ -68,8 +69,14 @@ export const cache = (options: {
   }
 
   return async function cache(c, next) {
-    const key = c.req.url
-    const cache = await caches.open(options.cacheName)
+    let key = c.req.url
+    if (options.keyGenerator) {
+      key = await options.keyGenerator(c)
+    }
+
+    const cacheName =
+      typeof options.cacheName === 'function' ? await options.cacheName(c) : options.cacheName
+    const cache = await caches.open(cacheName)
     const response = await cache.match(key)
     if (response) {
       return new Response(response.body, response)

src/test-utils/setup-vitest.ts

@@ -28,6 +28,10 @@ class MockCache {
     return this.store.get(key) || null
   }
 
+  async keys() {
+    return this.store.keys()
+  }
+
   async put(key: Request | string, response: Response): Promise<void> {
     this.store.set(key, response)
   }