middy-class-validator-middleware

A middy middleware that returns errors as http errors, compatible with http-errors.

This module is forked from https://github.com/dbartholomae/middy-middleware-class-validator. Thanks @Daniel (https://www.npmjs.com/~dbartholomae)
This module will be deleted once Daniel approved and merge additional features to the parent.

Installation

Download node at nodejs.org and install it, if you haven't already.

``sh
npm install middy-class-validator-middleware --save
`

Usage for body params

`typescript
// When using decorators, don't forget to import this in the very first line of code
import 'reflect-metadata';

import { APIGatewayProxyEvent } from 'aws-lambda';
import { IsString } from 'class-validator';
import middy from '@middy/core';
import JSONErrorHandlerMiddleware from 'middy-middleware-json-error-handler';

import ClassValidatorMiddleware, { WithBody } from 'middy-class-validator-middleware';

// Define a validator for the body via class-validator
class NameBody {
public firstName: string;

public lastName: string;
}

// This is your AWS handler
async function helloWorld (event: WithBody) {
// Thanks to the validation middleware you can be sure body is typed correctly
return {
body: Hello ${event.body.firstName} ${event.body.lastName},
headers: {
'content-type': 'text',
},
statusCode: 200,
};
}

// Let's "middyfy" our handler, then we will be able to attach middlewares to it
export const handler = middy(helloWorld)
.use(
ClassValidatorMiddleware({
// Add the validation class here
classType: NameBody,
}),
)
// The class validator throws validation errors from http-errors which are compatible with
// the error handler middlewares for middy
.use(JSONErrorHandlerMiddleware());
`

Usage for query params

`typescript
// When using decorators, don't forget to import this in the very first line of code
import 'reflect-metadata';

import { APIGatewayProxyEvent } from 'aws-lambda';
import { IsString } from 'class-validator';
import middy from '@middy/core';
import JSONErrorHandlerMiddleware from 'middy-middleware-json-error-handler';

import ClassValidatorMiddleware, { WithQuery } from 'middy-class-validator-middleware';

// Define a validator for the body via class-validator
class NameBody {
public firstName: string;

public lastName: string;
}

// This is your AWS handler
async function helloWorld (event: WithQuery) {
// Thanks to the validation middleware you can be sure queryStringParameters is typed correctly
return {
queryStringParameters: Hello ${event.queryStringParameters.firstName} ${event.queryStringParameters.lastName},
headers: {
'content-type': 'text',
},
statusCode: 200,
};
}

// Let's "middyfy" our handler, then we will be able to attach middlewares to it
export const handler = middy(helloWorld)
.use(
ClassValidatorMiddleware({
// Add the validation class here
queryClassType: NameBody,
queryValidationOptions: {
validator: { whitelist: true, forbidNonWhitelisted: false },
},
}),
)
// The class validator throws validation errors from http-errors which are compatible with
// the error handler middlewares for middy
.use(JSONErrorHandlerMiddleware());
``