From d71df884a1eac7b8c4d829e16ed804a6f8b15982 Mon Sep 17 00:00:00 2001
From: TheTimmaeh <TheTimmaeh@users.noreply.github.com>
Date: Wed, 21 Jul 2021 21:40:59 +0200
Subject: [PATCH] Delivering original content-type

---
 index.js      |  3 ++-
 index.test.js | 25 +++++++++++++++++++++++++
 2 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/index.js b/index.js
index e26ad75..cb0afb3 100644
--- a/index.js
+++ b/index.js
@@ -66,7 +66,7 @@ function createOnRequestHandler({ttl, additionalCondition: {headers}}) {
         const cached = JSON.parse(cachedString)
         res.header(X_RESPONSE_CACHE, X_RESPONSE_CACHE_HIT)
 
-        return res.code(cached.statusCode).send(cached.payload)
+        return res.code(cached.statusCode).header('Content-Type', cached.contentType).send(cached.payload)
       } else {
         res.header(X_RESPONSE_CACHE, X_RESPONSE_CACHE_MISS)
       }
@@ -91,6 +91,7 @@ function createOnSendHandler({ttl, additionalCondition: {headers}}) {
       key,
       JSON.stringify({
         statusCode: res.statusCode,
+        contentType: res.getHeader('Content-Type'),
         payload,
       }),
       ttl,
diff --git a/index.test.js b/index.test.js
index e8bba72..33790a8 100644
--- a/index.test.js
+++ b/index.test.js
@@ -195,3 +195,28 @@ test('should not waiting for cache due to timeout', (t) => {
     t.deepEqual(response2.data, {hello: 'world'})
   })
 })
+
+test('should keep the original content type', (t) => {
+  t.plan(6)
+  const instance = fastify()
+  instance.register(plugin, {ttl: 1000})
+  instance.get('/contentType', (req, res) => {
+    res.send({hello: 'world'})
+  })
+  instance.listen(0, async (err) => {
+    if (err) t.threw(err)
+    instance.server.unref()
+    const portNum = instance.server.address().port
+    const address = `http://127.0.0.1:${portNum}/contentType`
+    const [response1, response2] = await Promise.all([
+      axios.get(address),
+      axios.get(address),
+    ])
+    t.is(response1.status, 200)
+    t.is(response2.status, 200)
+    t.is(response1.headers['content-type'], 'application/json; charset=utf-8')
+    t.is(response2.headers['content-type'], 'application/json; charset=utf-8')
+    t.deepEqual(response1.data, {hello: 'world'})
+    t.deepEqual(response2.data, {hello: 'world'})
+  })
+})