From a78d361195827703053fc9b14a7affeaac77d0c8 Mon Sep 17 00:00:00 2001
From: Gregor <gregor@martynus.net>
Date: Thu, 1 Nov 2018 12:14:53 -0700
Subject: [PATCH] fix: avoid headers already sent error

---
 lib/proxy.js | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/lib/proxy.js b/lib/proxy.js
index 861fab3..15dca7f 100644
--- a/lib/proxy.js
+++ b/lib/proxy.js
@@ -27,9 +27,11 @@ function proxy (state, { target }) {
     onError (error, request, response) {
       /* istanbul ignore if */
       if (error.message.indexOf('Nock: No match for request') !== 0) {
-        response.writeHead(404, {
-          'Content-Type': 'application/json; charset=utf-8'
-        })
+        if (!response.headerSent) {
+          response.writeHead(500, {
+            'Content-Type': 'application/json; charset=utf-8'
+          })
+        }
 
         return response.end(JSON.stringify({
           error: error.message