fixed unresponsive server #3283

lib/reply.js

@@ -377,8 +377,8 @@ function preserializeHookEnd (err, request, reply, payload) {
 }
 
 function onSendHook (reply, payload) {
-  reply[kReplySent] = true
   if (reply.context.onSend !== null) {
+    reply[kReplySent] = true
     onSendHookRunner(
       reply.context.onSend,
       reply.request,

test/reply-error.test.js

@@ -525,3 +525,73 @@ test('should trigger error handlers if a sync route throws any non-error object'
   t.equal(reply.statusCode, 500)
   t.equal(JSON.parse(reply.body).foo, 'bar')
 })
+
+// Issue 3283 https://github.com/fastify/fastify/issues/3283
+test('setting content-type on reply object should not hang the server case 1', t => {
+  t.plan(2)
+  const fastify = Fastify()
+
+  fastify.get('/', (req, reply) => {
+    reply
+      .code(200)
+      .headers({ 'content-type': 'text/plain; charset=utf-32' })
+      .send(JSON.stringify({ bar: 'foo', baz: 'foobar' }))
+  })
+
+  fastify.inject({
+    url: '/',
+    method: 'GET'
+  }, (err, res) => {
+    t.error(err)
+    t.equal(res.statusCode, 200)
+  })
+})
+
+test('setting content-type on reply object should not hang the server case 2', t => {
+  t.plan(2)
+  const fastify = Fastify()
+
+  fastify.get('/', (req, reply) => {
+    reply
+      .code(200)
+      .headers({ 'content-type': 'text/plain; charset=utf-8' })
+      .send({ bar: 'foo', baz: 'foobar' })
+  })
+
+  fastify.inject({
+    url: '/',
+    method: 'GET'
+  }, (err, res) => {
+    //  the server should not hang and send a 500 reply
+    t.error(err)
+    t.same(
+      {
+        error: 'Internal Server Error',
+        message: 'Attempted to send payload of invalid type \'object\'. Expected a string or Buffer.',
+        statusCode: 500,
+        code: 'FST_ERR_REP_INVALID_PAYLOAD_TYPE'
+      },
+      JSON.parse(res.payload)
+    )
+  })
+})
+
+test('setting content-type on reply object should not hang the server case 3', t => {
+  t.plan(2)
+  const fastify = Fastify()
+
+  fastify.get('/', (req, reply) => {
+    reply
+      .code(200)
+      .headers({ 'content-type': 'application/json' })
+      .send({ bar: 'foo', baz: 'foobar' })
+  })
+
+  fastify.inject({
+    url: '/',
+    method: 'GET'
+  }, (err, res) => {
+    t.error(err)
+    t.equal(res.statusCode, 200)
+  })
+})