import { CognitoUserPoolTriggerEvent, Handler, Context, Callback } from 'aws-lambda';

const allowedDomains = ['hoge.ne.jp']

export const handler: Handler = (
        event: CognitoUserPoolTriggerEvent,
        context: Context,
        callback: Callback) => {
    // PreSignUp_SignUp
    if (event.triggerSource == 'PreSignUp_SignUp') {
        if (event.request.userAttributes &&
            event.request.userAttributes.email &&
            allowedDomains.some((_) =>
                    event.request.userAttributes.email.endsWith('@' + _))) {
                context.done(undefined, event);
        } else {
            var error = new Error('domain validation error');
            context.done(error, event);
        }
    }
};