Birmingham | 26-Jul-SDC | Merve Reis | Sprint 2 | Chat-App CYF-1162 by mervereis · Pull Request #121 · CodeYourFuture/Module-Decomposition

mervereis · 2026-09-16T14:10:21Z

Learners, PR Template

Self checklist

I have titled my PR with Region | Cohort | FirstName LastName | Sprint | Assignment Title
My changes meet the requirements of the task
I have tested my changes
My changes follow the style guide

Task code

Task ID : CYF-1162

Features:

Send chat messages
View existing message history
Reply message
Like and dislike messages

- Added backend with Express server and message handling routes - Implemented message sending, fetching, and reacting functionalities - Created frontend HTML structure for chat interface - Developed JavaScript for message rendering and user interactions - Styled chat application with CSS for better user experience

… handling

- Added package.json for backend with necessary dependencies (express, cors, crypto). - Implemented server.js for handling message retrieval, sending, and reactions with long-polling support. - Created index.html for the frontend chat interface with a message input area and display for chat messages. - Developed script.js to manage message fetching, sending, and user interactions (like, dislike, reply). - Styled the chat application with style.css for a user-friendly interface.

LonMcGregor

Good start, but I encountered some issues during testing. I also have some questions about your code.

Part of the task is to deploy the app. Is the chat app deployed anwhere we can test it? It's usually a good idea to include this in the PR text.

LonMcGregor · 2026-10-07T09:52:45Z

+	<script src="script.js" defer></script>
+</head>
+
+<body>


Did you try running the lighthouse tool? Does it offer any suggestions for accessibility fixes?

I did some changes and score is 100 now. @LonMcGregor

LonMcGregor · 2026-10-07T09:55:45Z

When trying to self-deploy the frontend, I get a couple of errors. A CORS policy error, and a error with long polling. Do you also see these? Is there something I need to configure?

LonMcGregor · 2026-10-07T09:56:21Z

+const messagesById = new Map(messages.map((msg) => [String(msg.id), msg]));
+const waitingClients = [];
+
+// Date.now() aynı milisaniyede çakışabilir, timestamp'leri tekilleştiriyoruz


As a general suggestion, if you are developing code that will be read by other english speakers it's a good idea to make your comments english as well.

removed the comment thanks .

LonMcGregor · 2026-10-07T10:04:56Z

+  return lastTimestamp;
+}
+
+function releaseWaitingClients() {


Can you explain what releaseWaitingClients is for?

releaseWaitingClients() handles clients waiting on a long-polling /getMessages request. When a message is sent or a reaction changes, it clears their timeouts and immediately responds with messages newer than each client’s since timestamp. This lets clients receive updates without continuously polling. @LonMcGregor

LonMcGregor · 2026-10-07T10:05:44Z

+    return;
+  }
+
+  if (!longPoll) {


How are you using the longPoll query parameter here? What's the difference of if it is true or false?

The longPoll query parameter controls what happens when there are no messages newer than since. If it’s false, the server immediately responds with an empty array. If it’s true, the server keeps the request open for up to 25 seconds and responds when an update arrives—or returns an empty array when the timeout expires. If new messages already exist, it responds immediately either way. @LonMcGregor

LonMcGregor · 2026-10-07T10:06:39Z

+  );
+
+  if (likeButton) {
+    likeButton.textContent = `👍 ${message.likes || 0}`;


Generating the like text is re-used multiple times in the app, is that a maintainable approach?

You’re right—the reaction button text and accessible label were duplicated. I’ve moved that logic into updateReactionButton() and now use it both when messages are first rendered and when reaction counts update. This keeps both paths consistent.

mervereis added 6 commits September 10, 2026 23:07

feat: add Dockerfile for backend setup

649db14

feat: implement long-polling for message retrieval and update message…

39df628

… handling

fix: update CORS configuration to remove unused origins

c22864b

fix: update server and client URLs for deployment

835930f

fix: improve message filtering and update handling in polling function

d164cad