Router Checker

Router-Checker is a express middlaware package for providing a way to validate requests before the logic of your application

Instalation

You can install router-checker through the npm registry. using npm or yarn

npm install router-checker

or

yarn add router-checker

Usage

If the request does not match with the Check object it will return an array with the error witch can be handled later in an error handler middlaware

simple exemple

import express from "express";
import { Check } from "router-checker";

const app = express();

app.use(express.json());


app.post("/myvalidatedapi",
     Check({
        body: {
            name: {
                type: "string",
                nullable: false,
                validator: (val : any) => {
                    return val.length > 5;
                }   
            }
        }
     }),
    (req, res) => {
        const { name, isFoo } = req.body;
            return res.status(200).send(`Hi ${name}, thanks for using our package!`);
    }
    );

app.use((err, req, res, next) => {
    // if something fail in the request checker you can handle it here
    return res.status(500).send("something went wrong :(");
});

const PORT = process.env.PORT || 3030;
app.listen(PORT, () => {
    console.log(`listening on port ${PORT}`);
});

The Checker Object

The checker object is the object that you'll pass through the Check function. It has the ParamChecker, QueryChecker and the BodyChecker interface.

In the case bellow, the request must have a query param with the name of id /myendpoint?id=1234 with can be transalated to a string and the body must have an object with properties called objProperty1 witch must be a number and objProperty2 witch must be a string.

import { Checker } from "router-checker";

export const createUserChecker : Checker = {
    query: {
        id: {
            type: "string",
            nullable: false
        },
    },
    body: {
        obj: {
            type: {
                objProperty1: {
                    type: "number",
                    nullable: true,
                },
                objProperty2: {
                    type: "string",
                    nullable: false,
                }
            }
        }
    }
};

validator function

In case you need more complex validation, like checking the length of a string or the validation of an email you can use the validator function, it's a function that receives the value in the param and return a boolean, in the case that the value returned is true, the validator will let it pass, if its false, it'll throw an error.

import { Checker } from "router-checker";

export const myChecker : Checker = {
    body: {
        myString: {
            type: "string",
            // Checks if the string is longer than 6 caracteres
            validator: (param : string) => {
                return param.length > 6;
            }
        }
    }
};

I know there are (a lot of) grammatical errors here, I'll fix it later. english is not my native language.