feat(defineCachedEventHandler): add event.context.cache (#2519)

Co-authored-by: Pooya Parsa <pooya@pi0.io>

src/runtime/cache.ts

@@ -370,6 +370,9 @@ export function defineCachedEventHandler<
           fetch: globalThis.$fetch,
         })) as $Fetch<unknown, NitroFetchRequest>;
       event.context = incomingEvent.context;
+      event.context.cache = {
+        options: _opts,
+      };
       const body = (await handler(event)) || _resSendBody;
 
       // Collect cachable headers

src/types/h3.ts

@@ -1,4 +1,4 @@
-import type { CaptureError, CapturedErrorContext } from "../runtime/types";
+import type { CacheOptions, CaptureError, CapturedErrorContext } from "../runtime/types";
 import type { NitroFetchRequest, $Fetch } from "./fetch";
 
 export type H3EventFetch = (
@@ -25,6 +25,10 @@ declare module "h3" {
       /** @experimental */
       errors: { error?: Error; context: CapturedErrorContext }[];
     };
+
+    cache: {
+      options: CacheOptions;
+    };
   }
 }
 

test/fixture/api/cached.ts

@@ -1,3 +1,6 @@
-export default defineCachedEventHandler(() => {
-  return Date.now();
+export default defineCachedEventHandler((event) => {
+  return {
+    timestamp: Date.now(),
+    eventContextCache: event.context.cache,
+  };
 });

test/tests.ts

@@ -643,7 +643,11 @@ export function testNitro(
     it.skipIf(ctx.isIsolated)(
       "should setItem before returning response the first time",
       async () => {
-        const { data: timestamp } = await callHandler({ url: "/api/cached" });
+        const {
+          data: { timestamp, eventContextCache },
+        } = await callHandler({ url: "/api/cached" });
+
+        expect(eventContextCache?.options.swr).toBe(true);
 
         const calls = await Promise.all([
           callHandler({ url: "/api/cached" }),
@@ -652,7 +656,8 @@ export function testNitro(
         ]);
 
         for (const call of calls) {
-          expect(call.data).toBe(timestamp);
+          expect(call.data.timestamp).toBe(timestamp);
+          expect(call.data.eventContextCache.options.swr).toBe(true);
         }
       }
     );