Channel Naming Scheme for a Messaging Application

Context

You are designing the channel structure for a PubNub-based messaging application. The app supports:

• One-on-one private conversations between any two users
• Group chat rooms with descriptive names
• Per-user notification channels

User IDs are alphanumeric strings like "user_abc123". The system will have thousands of users, and any two users should be able to start a private conversation.

Task

Write a JavaScript utility module (channel-utils.js) that provides functions to generate channel names for each of the three channel types. Include documentation comments explaining the naming conventions and any constraints. Ensure the naming scheme works correctly regardless of which user initiates a private conversation.

Expected Outputs

• A channel-utils.js file with exported helper functions for generating channel names for private conversations, group chats, and user notification channels.