@fastify-reply-from JSON Content-Type parsing confusion

@@ -3,6 +3,7 @@
 const fp = require('fastify-plugin')
 const { lru } = require('tiny-lru')
 const querystring = require('fast-querystring')
+const fastContentTypeParse = require('fast-content-type-parse')
 const Stream = require('node:stream')
 const buildRequest = require('./lib/request')
 const {
@@ -107,15 +108,13 @@ const fastifyReplyFrom = fp(function from (fastify, opts, next) {
         body = this.request.body
       } else {
         // Per RFC 7231 §3.1.1.5 if this header is not present we MAY assume application/octet-stream
-        const contentType = req.headers['content-type'] || 'application/octet-stream'
-        // detect if body should be encoded as JSON
-        // supporting extended content-type header formats:
-        // - https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Type
-        const lowerCaseContentType = contentType.toLowerCase()
-        const plainContentType = lowerCaseContentType.indexOf(';') > -1
-          ? lowerCaseContentType.slice(0, lowerCaseContentType.indexOf(';'))
-          : lowerCaseContentType
-        const shouldEncodeJSON = contentTypesToEncode.has(plainContentType)
+        let contentType = 'application/octet-stream'
+        if (req.headers['content-type']) {
+          const plainContentType = fastContentTypeParse.parse(req.headers['content-type'])
+          contentType = plainContentType.type
+        }
+
+        const shouldEncodeJSON = contentTypesToEncode.has(contentType)
         // transparently support JSON encoding
         body = shouldEncodeJSON ? JSON.stringify(this.request.body) : this.request.body
         // update origin request headers after encoding

@@ -53,6 +53,7 @@
   "dependencies": {
     "@fastify/error": "^3.0.0",
     "end-of-stream": "^1.4.4",
+    "fast-content-type-parse": "^1.1.0",
     "fast-querystring": "^1.0.0",
     "fastify-plugin": "^4.0.0",
     "pump": "^3.0.0",

@@ -0,0 +1,47 @@
+'use strict'
+
+const t = require('tap')
+const fastify = require('fastify')
+const get = require('simple-get').concat
+const From = require('..')
+
+const upstream = fastify()
+t.teardown(upstream.close.bind(upstream))
+t.plan(4)
+
+upstream.post('/test', async (request, reply) => {
+  if (typeof request.body === 'object') {
+    return 'not ok'
+  }
+  return 'ok'
+})
+
+upstream.listen({ port: 0 }, function (err) {
+  t.error(err)
+
+  const app = fastify()
+  app.register(From)
+  t.teardown(app.close.bind(app))
+
+  app.post('/test', (request, reply) => {
+    if (request.body.method === 'invalid_method') {
+      return reply.code(400).send({ message: 'payload contains invalid method' })
+    }
+    reply.from(`http://127.0.0.1:${upstream.server.address().port}/test`)
+  })
+
+  app.listen({ port: 0 }, function (err) {
+    t.error(err)
+
+    get({
+      url: `http://127.0.0.1:${app.server.address().port}/test`,
+      headers: { 'content-type': 'application/json ; charset=utf-8' },
+      // eslint-disable-next-line no-useless-escape
+      body: '"{\\\"method\\\":\\\"invalid_method\\\"}"',
+      method: 'POST'
+    }, (err, res, data) => {
+      t.error(err)
+      t.equal(data.toString(), 'ok')
+    })
+  })
+})