HL7-1: add comments to code

packages/server/config.ts

@@ -1,23 +1,25 @@
+
+// define available configurations
 interface Config {
     port: number;
     prefixes: string[];
     poolSize: number;
 }
 
+// construct config object from environment variables
 export const config: Config = {
     port: parseInt(process.env.PORT || '8080', 10),
     prefixes: (process.env.PREFIXES || 'STA').split(","),
     poolSize: parseInt(process.env.POOL_SIZE || '100', 10),
 };
 
+// validate config
 if (isNaN(config.port) || config.port < 1024 || config.port > 49151) {
     throw new Error('Invalid PORT environment variable (1024 - 49151)');
 }
-
 if (config.prefixes.length === 0) {
     throw new Error('Invalid PREFIXES environment variable (length > 1)');
 }
-
 if (isNaN(config.poolSize) || config.poolSize < config.prefixes.length) {
-    throw new Error('Invalid PORT environment variable (poolSize >= prefix.length)');
+    throw new Error('Invalid pool size environment variable (poolSize >= prefix.length)');
 }

packages/server/index.ts

@@ -17,6 +17,7 @@ for (const prefix of config.prefixes) {
     }
 }
 
+// mixes the array randomly to avoid getting the same ID reassigned
 function shake(arr: any[]) {
     for (let i = arr.length - 1; i > 0; i--) {
         const j = Math.floor(Math.random() * (i + 1));
@@ -71,9 +72,11 @@ wss.on('connection', (ws) => {
 
     console.log(`Client connected. Assigning ID: ${stationId}`);
 
+    // listen for messages and defined message handling
     ws.on('message', (message) => {
         try {
 
+            // parse every message to type Message
             const parsedMessage: Message = JSON.parse(message.toString());
             console.log(`Received message from ${stationId}:`, parsedMessage);
 
@@ -81,6 +84,7 @@ wss.on('connection', (ws) => {
             if (parsedMessage.type === MessageType.send_hl7v2) {
 
                 const { message } = parsedMessage.payload;
+
                 // TODO: validate message
 
                 // get sender and recipient ID
@@ -98,6 +102,7 @@ wss.on('connection', (ws) => {
                 // Find the recipient's WebSocket connection in our map.
                 const recipientWs = clients.get(recipientId);
 
+                // check if recipient exists and is connected
                 if (recipientWs && recipientWs.readyState === WebSocket.OPEN) {
 
                     // The recipient is connected. Forward the message.
@@ -136,6 +141,7 @@ wss.on('connection', (ws) => {
         if (stationId) {
             availableIds.push(stationId);
         }
+        // shake IDs to avoid getting the same ID reassigned
         availableIds = shake(availableIds);
     });