Restla

Introduction

Restla is a full-stack Node.js web framework written in TypeScript. It is specifically designed for developing the backend REST APIs of web applications.

Rather than reinvent the wheel, Restla provides a solid foundation that simplifies and integrates existing libraries commonly used in Node.js development. Restla integrates the Koa web framework and Squell, a type-safe wrapper for the Sequelize SQL ORM, to provide a completely promise-driven API that supports the async/await paradigm.

Restla extends Koa 2.x with additional functionality, but Koa's core functionality remains the same. This means you can use any official or third-party Koa middleware with Restla. By default, Restla applications have the following Koa middleware enabled:

• koa-bodyparser 3.x
• koa-router 7.x

Features

• All Koa middleware works out of the box with Restla applications.
• Resource, a router that can generate generic REST resource routes from a Squell model. The default functionality can easily be change by extending the Resource class.
• Auth, an authentication helper that is backend agnostic (i.e. you could authenticate with a third-party authentication.

Installation

npm install --save restla

Usage

Error Handling

By default Restla catches all error during requests, coerces them into ApplicationErrors if they're not already an application error and then sends them to the client with a response similar to:

{
  "message": "Some error message",
  "errors": []
}

Restla automatically coerces ModelSafe validation errors into a 400 response and any authentication errors into 402 responses. Any other unknown errors are then turned into 500 errors. The validation error response (400 bad request) looks similar to the above but is populated with error messages for each field:

{
  "message": "Validation failed",
  "errors": [{
    "path": "name",
    "message": "Is required"
  }]
}

If you hit any errors you should reject (or throw if you're using the async keyword) with an an ApplicationError in your route or resource. It takes a status code and error message like so:

throw new ApplicationError(404, 'Not Found');

Restla will automatically catch any rejected errors and send them using the ApplicationContext's error method. You can provide your own error response handling method by passing in a custom ApplicationContext when instantiating a Restla application.

Documentation

The API documentation generated using TypeDoc is available online.

To generate API documentation from the code into the docs directory, run:

npm run docs

Testing

First install the library dependencies and the SQLite3 library:

npm install
npm install sqlite3

To execute the test suite using SQLite as the backend, run:

npm run test