api.md

Overview

This module provides utilities for handling and writing Server-Sent Events (SSE) messages. It defines interfaces for messages, event options, and an event notifier, as well as a class for writing these messages.

Interfaces and Types

Message:

• data: The main content of the message. It can be a string or an object.
• comment (optional): A comment associated with the message.
• event (optional): The type of event for this message.
• id (optional): An identifier for the message.
• retry (optional): A number indicating how long to wait before retrying.

EventOptions:

• beforeFn (optional): A function to be executed before the main event function.
• afterFn (optional): A function to be executed after the main event function.

EventNotifier:

This interface defines methods for different types of events: update, complete, error, and close. Each method accepts a message and optional event options.

CustomFn:

A type representing a custom function that accepts data and returns any value.

Class: Writer

This class implements the EventNotifier interface and provides methods to write SSE messages.

Constructor:

• writer: A writable stream writer.
• encoder: A text encoder to encode messages.

Methods:

• writeMessage: Writes the provided message to the stream.
• update: Writes an update message.
• complete: Writes a completion message and closes the writer.
• error: Writes an error message and closes the writer.
• close: Closes the writer without writing a message.

Factory Function

getSSEWriter: A utility function that returns a new instance of the Writer class.