request-has v0.0.2

Simple request body / session validation middleware for Express

Quick Start

const app = express();
const {bodyMustHave, sessionMustHave} = require('request-has');

const {logIn, logOut} = require('./auth/log-in-log-out.js');

app.get('/log-in', bodyMustHave('username password'), logIn);
app.get('/log-out', sessionMustHave('userId'), logOut);

app.get('/profile', ifSessionHas('emailUserId'), emailUserProfile);
app.get('/profile', ifSessionHas('regularUserId'), regularUserProfile);

The following functions are available:

• bodyMustHave(properties): Stops the request if there is no request body, or if properties are missing. Returns status code 400 (Bad Request) with the message "No request body" or a list of missing body property names.
• ifBodyHas(properties): Validates the request body in the same way, but proceeds to the next route if the criteria is not met.
• sessionMustHave(properties): Stops the request if there is no req.session or if any listed properties are missing. Returns status code 401 (Unauthorized) with only a message "Unauthorized".
• sessionMustHave(properties, errCode): Validates the req.session object in the same way, but uses errCode for the status code and sends the standard message.
• ifSessionHas(properties): Validates the req.session object in the same way, but proceeds to the next route if the criteria is not met.

All above functions look for properties on req.session or req.body, as appropriate. They assume the body has already been parsed with express.json(), and that a session has been added to the request object using request-session or similar.

The properties argument can be an array of property names, or a space-delimited string. The following are equivalent:

app.get('/log-in', bodyMustHave('username password'), logIn); // space-delimited string
app.get('/log-in', bodyMustHave(['username','password']), logIn); // array of strings

If no properties are passed, they simply check that req.body or req.session exist. Note that for use with express-session, req.session will always exist on the request object and simply checking for its presence does not mean that the session has been saved or otherwise initiated. See express-session documentation for details.

Behavior

All functions proceed to the next middleware if req.body or req.session are present and either:

• Have all required properties, or
• Don't require any properties

They consider the request invalid if any of the following occur:

• req.body or req.session is missing entirely
• Any listed property is absent
• A listed property is present, but explicitly set to undefined

Note: If the property is present, any falsy value other than undefined is considered to be valid, such as an empty string.

The functions behave differently when they see an invalid request:

• bodyMustHave blocks the request. It sets a status code 400 (Bad Request) for any invalid request. It responds to the user with "no request body", or "request body needs:" and a list of missing property names.
• sessionMustHave blocks the request. If no errCode argument is provided, it assumes 401 and sets the response status code and responds with the standard message for that code.
• ifBodyHas and ifSessionHas do not block the request. They both execute next('route') and Express proceeds with the next route.