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.