Overview:

Express Promise Router is a package that simplifies writing route handlers for Express 4 by allowing middleware to return promises. This eliminates the need for duplicate code and provides support for handling promises, async/await, error handling, and more.

Features:

Simplified Middleware: Middleware and route handlers can return promises for asynchronous operations.
Error Handling: Supports custom error handlers similar to regular express.Router functionality.
ES6 Imports: Can be imported via ES6 imports for modern JavaScript development.
Support for Async/Await: Enables the use of async/await for enhancing code readability.
Promise Rejection Handling: Automatically calls next with the reason if a promise is rejected.
Calling Next: Supports calling next directly or using promises with "next" or "route" values.
Unit Testing Support: Provides guidelines for adding unit tests using mocha and chai.

Summary:

Express Promise Router is a useful tool for developers working with Express 4, offering a streamlined approach to handling promises in route handlers. With features like async/await support, error handling, and unit testing guidelines, this package enhances the development experience by reducing code duplication and providing a more efficient way to work with asynchronous operations in Express.