Sempervirens Endpoint

Middleware for handling Express routes, it provides an organized way to register multiple Express endpoints, an extendable class for isolating endpoint functionality, standardization for sending success and error objects, and built-in authorization with minimal JWT configuration.

Installation

npm install @sempervirens/endpoint

Usage

The following steps provide minimal usage. It is recommneded to have separate files for each RequestHandler instance, and a separate endpoints file that imports the RequestHandler instances and exports an array of endpoint configurations. Also, while @sempervirens/endpoint may be used independently, or in conjunction with @sempervirens/site-loader, implementation of both is integrated and streamlined in @sempervirens/server.

Non-secure Endpoints

1. Import express and Node http (or use @sempervirens/server).

2. Import registerEndpoints and RequestHandler from @sempervirens/endpoint.

3. Create request handlers.

4. Create an array of endpoint configurations.

5. Create an Express app.

6. Register the endpoints with the app.

7. Start the server.

import express from 'express';
import http from 'http';

import { registerEndpoints, RequestHandler } from '@sempervirens/endpoint';

// Recommended usage, in a separate file
class TestRequestHandler extends RequestHandler {
  constructor({ req, res, data, isSecure }) {
    super({ req, res, data, isSecure });
    if (!this.isAuthorized) return;
    this.#init();
  }
  #init() {
    console.log(this.data);
    // -> { prop1: 'val1' }
    this.res.send('Success');
  }
}

// In another separate file
const endpoints = [
  {
    path: 'GET /api/test',
    handler: TestRequestHandler
    data: { prop1: 'val1' } // Passed into RequestHandler constructor
  }
];

const app = express();
registerEndpoints(app, endpoints);
http.createServer(app).listen(80, () => console.log('Listening'));

Secure Endpoints

Passing isSecure to the endpoint configuration secures the endpoint by requiring a Authorization Bearer ${token} header to be passed in the request. See @sempervirens/authorizer or @sempervirens/server for details.

1. Import express and Node http.

2. Import registerEndpoints and RequestHandler from @sempervirens/endpoint.

3. Import @sempervirens/authorizer.

4. Initialize authorizer;

5. Create request handlers.

6. Create a set of endpoint configurations.

7. Create an Express app.

8. Register the endpoints with the app.

9. Start the server.

import express from 'express';
import http from 'http';
import authorizer from '@sempervirens/authorizer';
import { registerEndpoints, RequestHandler } from '@sempervirens/endpoint';

// See @sempervirens/authorizer or @sempervirens/server for details
const jwtPublicKey = readFileSync('./security/jwt/jwtRS256.key.pub', 'utf8');
const jwtPrivateKey = readFileSync('./security/jwt/jwtRS256.key', 'utf8');
authorizer.init({ jwtPublicKey, jwtPrivateKey });

// Recommended usage, in a separate file
class TestRequestHandler extends RequestHandler {
  constructor({ req, res, data, isSecure }) {
    super({ req, res, data, isSecure });
    if (!this.isAuthorized) return;
    this.#init();
  }
  #init() {
    this.res.send('Success');
  }
}

// In another separate file
const endpoints = [
  {
    path: 'GET /api/test',
    handler: TestRequestHandler,
    isSecure: true
  }
];

const app = express();
registerEndpoints(app, endpoints);
http.createServer(app).listen(80, () => console.log('Listening'));

API

registerEndpoints (single function)

Prop	Type	Params	Description
registerEndpoints	function	app: Express app, endpoints: { path: string, handler: RequestHandler, data: object, isSecure: boolean }	Registers the endpoints on the Express app.

ErrorCodes (enum)

Prop	Type	Params	Description
SCRIPT_ERROR	string	n/a	Default error code for RequestHandler error(), it sends a generic Server error message to the client.
USER_ERROR	string	n/a	When specified as the code in RequestHandler error(), it sends the error message given in error: new Error('Message') to the client.

RequestHandler (class)

Prop	Type	Params	Description
constructor	function	{ req: Express request, res: Express response, data: {}, isSecure: boolean }	The main entry point that is called when the Express route is invoked. If data is given, it provides the data to all instances as this.data, and if the RequestHandler is of a SiteLoader instance, both data parameters are merged with the RequestHandler set taking precedence if they have any of the same properties.
send	function	{ message: string, data: object }	Sends a standardized response to the client with a message and data object. It only sends if an error has not occurred and if a message has not already been sent.
error	function	{ number: number, error: Error, code: ErrorCodes, suppressLog: boolean, status: number }	Sends a standardized error object to the client. Typically only number and error are needed. If code is USER_ERROR, then it sends the message for the given error; otherwise, it sends a generic Server error message. It also logs to the server console, which provides server-side logging. Status may also be specified, but usally a soft 200 with an error object is sufficient so as not to throw a hard HTTP error in the browser console.