Is it common for Express plugins/third-party modules to add properties or functions to the req, res, and app objects?

[Behrang Saeedzadeh]

Hi,

For example, Swagger Node adds a property named swagger to the req object:

function hello(req, res) {
    var name = req.swagger.params.name.value || 'stranger';
    var hello = util.format('Hello, %s', name);
    res.json(hello);
}

If this is common and conventional, what guidelines should I follow to make sure my plugin/middleware does not clash with another plugins injected properties or properties that might be added to req, res, and app objects in upcoming Swagger releases?

Thanks,

Behrang