gistfile1.js

module.exports = {
    'foo': function() {
        assert.response(app, {
            url: '/foo',
            method: 'PUT',
            headers: {
                'content-type': 'application/json'
            },
            data: '{bar: "baz"}'
        }, {
            status: 200
        }, function(res) {}
            // nothing yet
        );
    }
}

gistfile2.js

app.put('/foo', function(req, res, next) {
    console.log(req.body);
});

If you change "data" to "body" it'll work... I think...

oddly I named it "data" for the request, and "body" for the response haha :) go consistency go