Extract duplicated logic to method

Author: pachirel

Diff for: lib/http-proxy/passes/web-outgoing.js

@@ -83,32 +83,32 @@ module.exports = { // <--
    * @api private
    */
   writeHeaders: function writeHeaders(req, res, proxyRes, options) {
-    var rewriteCookieDomainConfig = options.cookieDomainRewrite;
+    var rewriteCookieDomainConfig = options.cookieDomainRewrite,
+        setHeader = function setHeader(key, header) {
+          if (header != undefined) {
+            if (rewriteCookieDomainConfig && key.toLowerCase() === 'set-cookie') {
+              header = common.rewriteCookieDomain(header, rewriteCookieDomainConfig);
+            }
+            res.setHeader(String(key).trim(), header);
+          }
+        };
+
     if (typeof rewriteCookieDomainConfig === 'string') { //also test for ''
       rewriteCookieDomainConfig = { '*': rewriteCookieDomainConfig };
     }
+
     // message.rawHeaders is added in: v0.11.6
     // https://nodejs.org/api/http.html#http_message_rawheaders
     if (proxyRes.rawHeaders != undefined) {
       for (var i = 0; i < proxyRes.rawHeaders.length; i += 2) {
         var key = proxyRes.rawHeaders[i];
         var header = proxyRes.rawHeaders[i + 1];
-        if (header != undefined) {
-          if (rewriteCookieDomainConfig && key.toLowerCase() === 'set-cookie') {
-            header = common.rewriteCookieDomain(header, rewriteCookieDomainConfig);
-          }
-          res.setHeader(String(key).trim(), header);
-        }
+        setHeader(key, header);
       };
     } else {
       Object.keys(proxyRes.headers).forEach(function(key) {
         var header = proxyRes.headers[key];
-        if (header != undefined) {
-          if (rewriteCookieDomainConfig && key.toLowerCase() === 'set-cookie') {
-            header = common.rewriteCookieDomain(header, rewriteCookieDomainConfig);
-          }
-          res.setHeader(String(key).trim(), header);
-        }
+        setHeader(key, header);
       });
     }
   },