joi-type-extract

Clone of https://github.com/TCMiranda/joi-extract-type

Setup

1. Install package

   1npm install @goodrequest/joi-type-extract
   2or
   3yarn add @goodrequest/joi-type-extract

2. Create ./src/types/joi/index.d.ts and import package in it, which will extend Joi types

   1import '@goodrequest/joi-type-extract'

3. Add this compiler option and include created file in tsconfig.json in typeRoots

   1{
   2	"compilerOptions": {
   3        "strictNullChecks": true,
   4		"typeRoots": [
   5			"./src/types"
   6		]
   7	}
   8}

Usage example

1import Joi from 'joi'
2
3export const requestSchema = () =>
4	Joi.object({
5		params: Joi.object({
6			userID: Joi.number().required()
7		}),
8		query: Joi.object({
9			search: Joi.string().required()
10		}),
11		body: Joi.object({
12			name: Joi.string().required()
13		})
14	})
15
16export const responseSchema = Joi.object({
17   messages: Joi.array().items({
18	   message: Joi.string().required(),
19	   type: Joi.string().valid(MESSAGE_TYPE.SUCCESS).required()
20   }).required()
21})
22
23type RequestType = Joi.extractType<ReturnType<typeof requestSchema>>
24type ResponseType = Joi.extractType<typeof fullMessagesResponseSchema>

Extracted EequestType and ResponseType can be then used in express.Request and express.Response types

1import { Request, Response, NextFunction } from 'express'
2
3const businessLogic = async (
4	req: Request<RequestType['params'], ResponseType, RequestType['body'], RequestType['query']>,
5	res: Response<ResponseType>,
6	next: NextFunction
7) => {
8	const { params, query, body } = req
9
10	// params.userID will have number type
11	// query.serch will have string type
12	// body.name will have string type
13
14	// response will be enforced to be same as ResponseType
15	return res.json({
16		messages: [
17			{
18				message: 'Response message',
19				type: MESSAGE_TYPE.SUCCESS
20			}
21		]
22	})
23}