express-require v1.0.4

express-require aims to save a lot of unnecessary typing when validating parameters, while avoiding bugs and vulnerabilities at the same time. To use the middleware on a route, simple call requirements() and pass it a list of requirements, like so:

myRouter.get('/test', requirements({query: [R.string('parameter1'), R.integer('parameter2', 4)]}), (request, response) => {
    response.send({
        parameter1: request.query.parameter1,
        parameter2: request.query.parameter2
    });
});

R is an object holding shorthand functions for default Requirement classes. Provide them a parameter name and optionally a fallback value that will be used when the parameter is undefined.

The Requirement class is designed to be easy to extend, allowing you to set up custom Requirements without much hassle. This could for example be used to interface with a user management system, restricting access to your routes:

class LoggedInRequirement extends Requirement {
    validate(request, type: ParameterType) {
        super.validate(request, type);
        
        if (typeof request.session.userID === 'undefined') {
            throw new RequirementException('You need to be logged in to access this resource!');
        }
    }
}