Serverless request validator

This is made to be used in Vercel serverless applications, it can be used with Javascript and Typescript.

To install it:

npm install serverless-request-validator

or

yarn add serverless-request-validator

Using the library

If you are using Javascript:

const Validate = require("serverless-request-validator");

With Typescript:

import Validate from "serverless-request-validator";

Handling one-method-only requests

If an endpoint in your app should only accept one HTTP method, use the property named as the only method allowed. For example:

Javascript

// /api/index.js
const Validate = require("serverless-request-validator")

// Only HTTP `GET` is allowed
module.exports = Validator.get((req, res)=>{
    res.send("get request")
})

Typescript

// /api/index.ts
import Validate from "serverless-request-validator";

// Only HTTP `GET` is allowed
export default Validate.get((req, res)=>{
    res.send("get request")
})

The default export means that the application endpoint will only allow a request using the GET method. If a request is made using a different method, it will respond with a 405 (method not allowed) status code, and saying the method can't be used in that url (like in Express)

Handling multi-method requests

This makes it possible for an endpoint to handle requests of different methods. Very similar to the previous example:

Javascript

// /api/index.js
const Validate = require("serverless-request-validator")

// GET, POST and PUT are allowed.
module.exports = Validate({
  get(req, res) {
    res.send("a get request");
  },
  post(req, res) {
    res.send(`A ${req.method} request`);
  },
  put(req, res) {
    res.send("a put request");
  },
})

Typescript

// /api/index.ts
import Validate from "serverless-request-validator";

// GET, POST and PUT are allowed
export default Validate({
  get(req, res) {
    res.send("Hello");
  },
  post(req, res) {
    res.send(`A ${req.method} request`);
  },
  put(req, res) {
    res.send("a PUT request");
  },
})

In this case, this function will handle GET,POST and PUT methods sent to it. As in the previous example, other methods different that the allowed ones will send a 405 status code and the message saying the method can't be used in that url.

Sending files

It is possible to use the sendFile() method available

// /api/index.ts
import Validate from "serverless-request-validator";
import path from "path"

export default Validate.get((req,res)=>{
  res.sendFile(path.resolve(__dirname,"../src/cat.png"))
})

If a file doesn't exist, a 404 status code will be sent to the user

That's basically it, hopefuly it makes it easier to have different reponses for different methods=)