Merge pull request #553 from witheve/corey

Better messages for Eve server

Author: cmontella

src/runtime/server.ts

@@ -32,7 +32,7 @@ const contentTypes = {
 }
 
 const BROWSER = !argv["server"];
-const PORT = process.env.PORT || 8080;
+const PORT = process.env.PORT || argv["port"] || 8080;
 const serverDatabase = new ServerDatabase();
 const shared = new PersistedDatabase();
 
@@ -163,5 +163,13 @@ let wss = new WebSocketServer({server: server});
 initWebsocket(wss);
 
 server.listen(PORT, function(){
-  console.log("Server listening on: http://localhost:%s", PORT);
+  console.log(`Eve is available at http://localhost:${PORT}. Point your browser there to access the Eve editor.`);
+});
+
+// If the port is already in use, display an error message
+process.on('uncaughtException', function(err) {
+    if(err.errno === 'EADDRINUSE') {
+      console.log(`ERROR: Eve couldn't start because port ${PORT} is already in use.\n\nYou can select a different port for Eve using the "port" argument.\nFor example:\n\n> npm start -- --port 1234`);
+    }
+    process.exit(1);
 });