middy-middleware-class-validator

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

Installation

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

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

Documentation

There is additional documentation.

Usage

`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-middleware-class-validator";

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

@IsString()
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());
``