Database is in the Internal Layer?

[Cleanshooter]

According to your documentation the database interfaces are part of the internal layer. However per Martin's diagram and documentation on his blog the database is an external layer. So the question I have is, how is this an example of using clean architecture in a node.js app if you've changed the original authors definition of clean architecture by moving something he claims is external as an internal layer?

[lex0r]

@Cleanshooter to be fair, the author did mention why he moved it to the internal layer, and it's due to practicality reasons. But don't get fooled by this fact. When looking closer at the architecture one can see that despite raw database queries being made from data-access/students-db/* drivers (which strictly speaking should be placed under drivers/db), the architecture still follows the principle of dependency inversion. All these low-level DB operations meet the interface defined in data-access/students-db/index.js

module.exports = {
  listStudents,
  findStudent,
  findStudentsBy,
  addStudent,
  deleteStudent,
  dropAll
}

That means there's no violation of the clean architecture principles, and since I'm already writing this long comment here,I can speculate on the reason why the author didn't want to separate everything to make it "like in the book". This example is just too simple to introduce extra separation between application layer and data access layer, since all it does is transferring data back and forth.

[Cleanshooter]

Thanks for the response. I'm still evaluating this architecture and its parctical application in NodeJS apps, thus my question. I'm still struggling to find a practical use case for a full out, "like in the book", use for a pure Clean Architecture. Don't get me wrong there are aspects that make sense, like the data abstraction and the dependency inversion (to an extent) but it seems like taking IoC to the extreme, as Martin seems to be recommending, just isn't pratical.

One could have taken this to the next level of abstraction between the application and data access layers but I agree for this example it wouldn't be pratical. My question is whether it would ever be pratical using NodeJs?

[lex0r]

@Cleanshooter I'm not the right person to answer this question, all I can do is make logical assumptions :)

Let's have a look at the facts first.

1. Clean architecture really shines in big (bloody enterprise?) projects.
2. Big projects are more likely to succeed if they are done using a strictly typed language or they are made of multiple "services" in different tech (I'm cautious to not use the M buzzword).
3. Node is primarily a web services / API development tech, and quite popular when used this way

That brings my to a conclusion that when a team uses Node in their project, they are likely to build something relatively small (a [micro]service) rather than large. If they build something large they would probably use TypeScript. With that in mind, we can assume there aren't many real world Node projects that follow the clean architecture pattern.