Option to try to preserve the case of the headers.

Issue #67

index.js

@@ -69,6 +69,22 @@ app.all('*', (req, res) => {
  }
  };
 
+ if(process.env.PRESERVE_HEADER_CASE){
+ let newHeaders = {...req.headers};
+
+ // req.headers is in lowercase, processed, deduplicated. req.rawHeaders is not.
+ // Match on the preserved case of the header name, populate newHeaders with preserved case and processed value. 
+ for (let i = 0; i < req.rawHeaders.length; i += 2) {
+ let preservedHeaderName = req.rawHeaders[i];
+ if (preservedHeaderName == preservedHeaderName.toLowerCase()) { continue; }
+
+ newHeaders[preservedHeaderName] = req.header(preservedHeaderName);
+ delete newHeaders[preservedHeaderName.toLowerCase()];
+ }
+ echo.headers = newHeaders;
+ }
+
+
  //Add client certificate details to the output, if present
  //This only works if `requestCert` is true when starting the server.
  if(req.socket.getPeerCertificate){