Suppose we have a large to-do task manager app with many features. Say we have an entity, which is the task, and it has certain fields like: title, description, deadline, sub-tasks, dependencies, etc. This entity is used in many parts of our codebase.
Suppose we decided to modify this entity, either by modifying, removing, or adding a field. We may have to change most if not all of the code that deals with this entity. How can we do this in a way that protects us from errors and makes maintenance easy?
Bear in mind, this is just an example. The entity may be something more low-key, such as a logged user event in analytics, or a backend API endpoint being used in the frontend, etc.
Potential Solutions
Searching
One way people do this already is by just searching the entity across the codebase. This is not scalable, and not always accurate. You may get a lot of false positives, and some parts of the code may use the entity without using it by name directly.
Importing
Defining the entity in one central place, and importing it everywhere it is used. This will create an error if a deleted field remains in use, but it will not help us when, say, adding a new field and making sure it is used properly everywhere the entity is being used
so what can be done to solve this? plus points if the approach is compatible with Functional Programming
Automated Tests and CICD
Tests can discover these types of issues with high accuracy and precision. The downside is… Well tests have to be written. This requires developers to be proactive, and writing and maintaining tests is non-trivial and needs expensive developer time. It is also quite easy and common to write bad tests that give false positives.
Thanks for the tip! I think that is indeed what I need. Thank you :)
Oh are you talking about creating the object? Yeah I think you might get better answers in a TS thread, because that question and the response here makes no sense in most statically typed languages.
I am still confused about what OP is looking for. Even in typescript, if a new field is added and not used in other places, compilation will fail. Unless OP explicitly marks the field as optional.
There’s also the possibility that the codebase is littered with the “any” keyword (I’m not saying OP is doing it but I’ve definitely seen plenty of codebases that do this). If someone says they’re using typescript but their code is full of “any” keywords, they’re not using typescript. They’re just using plain JavaScript at that point.
That’s if the field is added but never used. If it is used in some parts of the codebase, but not used / handled in others, compilation will pass. I would prefer that it doesn’t. I would prefer that if such a change were to occur, that every part of the codebase that uses that entity is explicitly addressed by the change made.
Again, if there’s anything you don’t understand, feel free to ask me directly. I do not get notifications when you reply to a comment that isn’t mine.
If there’s anything that doesn’t make sense in my question, feel free to ask any questions or clarifications on any part of it.