Littless

This project is a helper for serverless services that is achieved through the usage of adapters.

Inspired by express middlewares and the idea was to be able to reuse some of them.

Install

npm install littless -S

Install an adapter

npm install littless-adapter-netlify -S

or

npm install littless-adapter-vercel -S

Usage

Netlify example

Create a functions/test.js

const littless = require('littless').default;
const adapter = require('littless-adapter-netlify').default;
const cookieParser = require('cookie-parser');
const {json} = require('body-parser');
const app = littless();

app.useAdapter(adapter);

app.use(json({
  extended: true
}));
app.use(cookieParser());
app.useAfter((req, res) => {
  if (!res.shouldOutput()) {
    res.status(500)
      .send({
        error: true,
        message: 'No body was sent up until this point'
      })
  }
});

exports.handler = app.any(async (req, res, next) => {
  console.dir(req);
  res.send({
    path: req.path,
    cookies: req.cookies,
    query: req.query,
    body: req.body
  });

  req.on('data', (chunck) => {
    console.log(chunck);
  })

  next();
});

Vercel example

Create a api/test.js

const littless = require('littless').default;
const adapter = require('littless-adapter-vercel').default;
const cookieParser = require('cookie-parser');
const app = littless();

app.useAdapter(adapter);
app.use(cookieParser());
app.useAfter((req, res) => {
  if (!res.shouldOutput()) {
    res.status(500)
      .send({
        error: true,
        message: 'No body was sent up until this point'
      })
  }
});

module.exports = app.any(async (req, res, next) => {
  res.send({
    path: req.path,
    cookies: req.cookies,
    query: req.query,
    body: req.body
  });

  next();
});

Please note that vercel already parses the body so no need to use the body-parser

Specify the method to use

You can use the already made middlewares to filter the allowed methods

app.get(/* ... */)

app.post(/* ... */)

app.put(/* ... */)

app.delete(/* ... */)

Or you can use only or except to construct your own

app.only(['POST', 'GET'], (req, res, next) => {
  /* ... */
})

app.except(['DELETE'], (req, res, next) => {
  /* ... */
})

Using adapters

Adapters can be used with .useAdapter

Available adapters

For now the available parsers are for netlify and vercel but you can inspect the adapters code and create your own.

If you do create a new parser please reach out to me so I can include it in the official list.

App Available Methods

Method	Arguments	Description
useAdapter	Adapter Class	(Required) Specify which adapter to be used to parse information from serverless service
use	Function(req, res, nextMiddleware)	Append middleware
useAfter	Function(req, res, nextMiddleware)	Append middleware to be used after the callback function
useBefore	Function(req, res, nextMiddleware)	Preprend middleware
post	Function(req, res, nextMiddleware)	Only allow POST and OPTIONS requests and calls back the first argument
get	Function(req, res, nextMiddleware)	Only allow GET and OPTIONS requests and calls back the first argument
delete	Function(req, res, nextMiddleware)	Only allow DELETE and OPTIONS requests and calls back the first argument
put	Function(req, res, nextMiddleware)	Only allow PUT and OPTIONS requests and calls back the first argument
any	Function(req, res, nextMiddleware)	Allows any requests and calls back the first argument
only	Methods (Array), Function(req, res, nextMiddleware)	Allows user to specify methods to allow and calls back the second argument
except	Methods (Array), Function(req, res, nextMiddleware)	Allows user to specify methods to block and calls back the second argument

Request Api

Method / Property	Type	Description
headers	Object	Request headers are accessible from this property
query	Object	Query params are accessible from this property
httpMethod	String	The method of the request
path	String	The url path
body	String / Object	Normally a string but can be parsed depending on the service or the adapter
raw	Object	The original event sent by the service

Response Api

Method	Arguments	Description
status	code:Number	Specify the response code
set	key:String, value:String	Sets a header for the response i.e res.set('Content-Type', 'application/json')
headers	key:String, value:String	Alias for set
send	body:Any	Sets the response body

Note: Possibly the response should have a way of setting a cookie but this can be achieved with the headers or creating a middleware for that which might be an option for the future.