update API response status code from 304 to 204 for cache hits

Author: jkyberneees

README.md

@@ -63,7 +63,7 @@ Calling the API
 
 ```bash
 curl -X POST http://localhost:3000/create -H "x-request-id: 123"  # 200 -> Resource created!
-curl -X POST http://localhost:3000/create -H "x-request-id: 123"  # 304
+curl -X POST http://localhost:3000/create -H "x-request-id: 123"  # 204
 # after 5 seconds
 curl -X POST http://localhost:3000/create -H "x-request-id: 123"  # 200 -> Resource created!
 ```

index.js

@@ -66,8 +66,8 @@ export function idempotencyMiddleware({
         .get(idempotencyKey)
         .then(function (cachedResponse) {
           if (cachedResponse) {
-            // Cached response found: return 304 Not Modified to prevent reprocessing
-            res.statusCode = 304
+            res.statusCode = 204
+            res.setHeader('X-Idempotency-Status', 'hit')
             res.setHeader('Content-Type', 'text/plain; charset=utf-8')
             res.end()
           } else {

test.js

@@ -110,8 +110,8 @@ test('idempotencyMiddleware - idempotency key present and cache hit', async (t)
   )
   assert.strictEqual(
     res.statusCode,
-    304,
-    'Should return 304 Not Modified if cache hit',
+    204,
+    'Should return 204 Not Modified if cache hit',
   )
   assert.strictEqual(
     res.headers['content-type'],