pitstop.js

An express middleware for creating conditional groups of other middleware.

Installation

NPM: npm install pitstop

Usage

pitstop([crew, [conditionFunction]])

Creates the pitstop. The initial middleware crew and run condition can be passed directly as arguments. Returns the pit middleware function object.

pit.use(middleware)

Adds a middleware to the pit crew. Middleware can be added individually, as multiple arguments, or in an array.

pit.use(morgan());
pit.use(cookieParser(), bodyParser());
pit.use([
    csrf(), errorHandler()
]);

Error handlers added to the pit will only catch errors that occur within the pit. If no error handler is defined, errors will bubble up to Express.

pit.condition(null|function|truthy)

Defines the condition for if the pit crew should run. If the passed value is undefined, null or a truthy value, the crew will always run. If the passed value is false, the pit will be bypassed.

If a function is provided, the function will be executed as a middleware and receive the request, response and callback arguments. Calling the callback with false or an error will bypass the pit. Calling without any value run the pit crew.

pit.execute

pit.execute is a bypass middleware which will skip the condition and always run the pit crew.

Example

The following example will only run session handling and user loading if a session cookie already exists on the request. Said cookie will only be created when the user logs into the site.

var express = require('express');
var pitstop = require('pitstop');
var passport = require('passport');
var flash = require('connect-flash');

var expressCookies = require('cookie-parser');
var expressSession = require("express-session");

// Note, some passport setup code has been omitted, as it is not relevant to the example.

var userSession = pitstop();
    .condition(function (req, res, next) {
        if (req.cookies.session) {
            next();
        } else {
            next(false);
        }
    })
    .use(expressSession({
        key: 'session'
    }))
    .use(flash())
    .use(passport.initialize())
    .use(passport.session())
    .use(function (req, res, next) {
        if (req.isAuthenticated()) {
            res.locals.user = req.user;
        }
        next();
    });


var app = express();

app.use(expressCookies);
app.use(userSession);

app.post('/login', userSession.execute, function (req, res) {
    // This route will always create/load a session.

    passport.authenticate('local', {
        successRedirect: req.session && req.session.goingTo || '/profile',
        failureRedirect: "/login",
        failureFlash: true
    })(req, res);
});

app.get('/', function (req, res) {
    // This route will only load a session if a session cookie exists,
    // which was created when they logged in.
});

Running Unit Tests

From inside the repository root, run npm install to install the test dependencies.

Run npm test to execute the complete test suite.