app.engine(ext, callback) Registers the given template engine callback as ext. By

app.delete(path, callback [, callback ...]) Routes HTTP DELETE requests to the specified path with the specified callback functions. For more

Define error-handling middleware functions in the same way as other middleware functions, except error-handling functions have four arguments instead of three: (err,

req.fresh Indicates whether the request is “fresh.” It is the opposite of req.stale. It is true

Node.js vulnerabilities directly affect Express. Therefore keep

app.on('mount', callback(parent)) The mount event is fired on a sub-app, when it is mounted on a parent app. The parent app is

res.clearCookie(name [, options]) Clears the cookie specified by name. For details about the options object, see

req.protocol Contains the request protocol string: either http or (for TLS requests) https. When

res.sendStatus(statusCode) Sets the response HTTP status code to statusCode and send its string representation as the response

router.param(name, callback) Adds callback triggers to route parameters, where name is the name of the parameter and callback