Before getting into actual code, we want to provide a heads up on the structure for the code in this chapter, which is a bit different than before, and we hope it adds another view to structure code for Express and Node.js in general.
Some may call it a Factory pattern; it consists of wrapping each of the file's code with a function that can be used to configure or test it. While this requires a bit more of scaffolding, it frees our code from depending on a static state. It will often look as follows:
'''javascript
module.exports = function (dependency1){
// these will be public
var methods = {}
// individual for each instance
var state = 0
// some core functionality of this file
methods.addToState = function(x) {
state += x
};
methods.getResult = function() {
return dependency1.getYforX(state)
};
return methods
}
'''A corollary of this structure is that each invocation of this file will have its own state, exactly like the instance of a class...