October 16, 2018 by Artur

Making backend with nodejs and typescript is trendy nowadays. In this article I will show you the way how to make it type safe and totaly connected with frontend within a short period of time.

To make this kind of backend I have to use my open source experimental tool slothking. First of all we will create a diagram for our backend. We will not use any extensions to make everything from scratch.

Go to Slothking App Register. Click out this diagram

Now if you have it. Save this with some fancy name. then go to slothking cli repo. Slothking CLI Download it and login.

$ sloth login username password

Create mongodb with docker

$ docker run --rm -it -p 27017 :27017 mongo:3

Next you have to clone backend starter or import it to your backend project it is up to you. If you want to procced with backend starter. Go ahead and download it

$ git clone https://github.com/slothking-online/backend-nodets-boilerplate $ cd backend-nodets-boilerplate $ npm install $ npm run dev

Open another tab in terminal.

$ sloth nodets your-project-name src/generated.ts

It will generate file with typeguard for your script hosting platform

import * as sloth from '@slothking-online/node' import * as tg from 'typegoose' import { ObjectId } from 'bson' export type ImpType = { _id ? : ObjectId code : string hash ? : string name ? : string } export class Imp extends tg . Typegoose { @tg . prop ( ) code : string @tg . prop ( ) hash : string @tg . prop ( ) name : string } export const Models = ( ) => ( { ImpModel : new Imp ( ) . getModelForClass ( Imp ) , } ) const slothking : { simpleImpServer : { name : string middlewares : { } endpoints : { get : sloth . SlothkingEndpoint < { name ? : string } , { } , { Imp : tg . InstanceType < Imp > } > createOrUpdate: sloth.SlothkingEndpoint< { Imp ? : ImpType } , { } , { Imp : tg . InstanceType < Imp > } > } } } = { simpleImpServer : { name : 'simpleImpServer' , middlewares : { } , endpoints : { get : { path : 'get' , middlewares : [ ] , } , createOrUpdate : { path : 'createOrUpdate' , middlewares : [ ] , } , } , } , } export default slothking

So you have type definitions and mongo generated. Lets start implementing our endpoints.

Create a file src/implement.ts

import generated , { Models , Imp } from './generated' import * as crypto from 'crypto' import { InstanceType } from 'typegoose' const models = Models ( ) const { simpleImpServer : { endpoints : { createOrUpdate , get } , } , } = generated createOrUpdate . run = async props => { const { Imp : { code , hash , name } , } = props . context . arguments let ImpInstance : InstanceType < Imp > if ( hash && name ) { ImpInstance = await models . ImpModel . findOneAndUpdate ( { hash , } , { code , } , { new : true , } ) } else { ImpInstance = await models . ImpModel . create ( { name , code , hash : crypto . randomBytes ( 8 ) . toString ( 'hex' ) , } ) } return { Imp : ImpInstance , } } get . run = async props => { const { name } = props . context . arguments return { Imp : await models . ImpModel . findOne ( { name , } ) , } } export { generated }

Now edit the src/index.ts file

import run from '@slothking-online/node' import { generated } from './implement' export default run ( [ generated . simpleImpServer ] , process . env . MONGO )

Now you have fully working gist-like server, in next tutorial I will show you how to create CLI for this kind of gist server.