NOTIFICATIONS.md

LISTEN/NOTIFY Support

This mock server implements PostgreSQL's asynchronous notifications for pub-sub style testing.

• Supported commands:
  • LISTEN channel_name;
  • UNLISTEN channel_name;
  • UNLISTEN *;
  • NOTIFY channel_name; or NOTIFY channel_name, 'payload';

Notes and behavior:

• Channel names follow PostgreSQL identifier rules (letters, digits, underscore; must start with letter/underscore).
• Payload is optional and must be a single-quoted string when provided; use doubled quotes to escape ('').
• Notifications are broadcast to all connections that executed LISTEN channel_name.
• When a connection closes, its listeners are removed automatically.
• UNLISTEN * removes all listeners for the connection.

Example session:

-- Session A
LISTEN events;

-- Session B
NOTIFY events, 'hello';

Testing locally with psql:

LISTEN jobs;
-- in another session
NOTIFY jobs, 'run';

Implementation details:

• See src/notification/notificationManager.js for channel and broadcast logic.
• Query parsing lives in src/handlers/queryHandlers.js for LISTEN/UNLISTEN/NOTIFY.
• Protocol notifications are sent via sendNotificationResponse.