Added rootDir option to renderCalderaApp (#10)

This commit creates a new option on the `renderCalederaApp` function
allowing users to set their own public directory. This allows
customization of the template, CSS, scripts, etc...

This change keeps the caledera-client.js being served from the Caledera
root directory.

Author: bradjasper

Diff for: src/server/index.tsx

@@ -30,11 +30,11 @@ export type Dispatch = (
 
 export const renderCalderaApp = (
   app: React.ReactElement,
-  options: { port?: number; hostname?: string } = {}
+  options: { port?: number; hostname?: string; rootDir?: string; } = {}
 ) => {
   const savedStates = new Map<SessionID, Buffer>();
   const server = http.createServer((req, res) =>
-    serve(req, res, finalhandler(req, res))
+    serve(req, res, finalhandler(req, res), options)
   );
   const wss = new WebSocket.Server({
     noServer: true,

Diff for: src/server/serve.ts

@@ -2,20 +2,24 @@ import { IncomingMessage, ServerResponse } from "http";
 import path from "path";
 import fs from "fs";
 
-const rootDir = path.resolve(__dirname, "..", "public");
+const calderaRootDir = path.resolve(__dirname, "..", "public");
 
 const serve = (
   req: IncomingMessage,
   res: ServerResponse,
-  onError: (err: any) => void
+  onError: (err: any) => void,
+  options: { rootDir?: string; } = {}
 ) => {
+  let rootDir = (options.rootDir ? options.rootDir : calderaRootDir);
+
   const url = req.url;
 
   let filePath = "index.html";
   let mimeType = "text/html";
 
   if (url === "/caldera-client.js") {
     filePath = url.slice(1);
+    rootDir = calderaRootDir;
     mimeType = "application/javascript";
   }