E-Mail from Chad Parry

email.txt

That looks great. Sorry it took me forever to take a look at it. 
One pedantic thing that I would change is that I would aim for immutability whenever possible. 
For example, ApplicationScope.setArgs (https://github.com/mdix/diy-di-typescript/blob/master/class/ApplicationScope.ts#L4) 
wouldn't be necessary if instead the ApplicationScope took the args in the constructor. 
That way, you are guaranteed that everything is initialized correctly throughout the entire program. 
Another pedantic thing I would watch out for is to purge your scope class of any logic. 
That includes array access, (https://github.com/mdix/diy-di-typescript/blob/master/class/Injector.ts#L17). 
Even though "getArgs()[0]" looks harmless, it's the beginning of an ArgumentParser class, and so that's where that logic usually belongs. 
Otherwise, more and more logic will creep in to your scope object.None of that logic will be testable. 
On the other hand, keeping the logic in an ArgumentParser class means you can test the corner cases, such as when there are zero arguments provided. 
Thanks for showing me the program!