Booking.com famously doesn’t write many tests at all. Something something move fäst. Well, other than the A/B kind. But you know what I mean. I also recall a recent Stack Overflow blog post mentioning that they don’t have many either.

Regarding a push against unit tests, the Frontend world, for what its worth, has a rising school of thought that favours integration tests based around what the user sees and interacts with.

Booking.com is one of the most horrifically unreliable, buggy pieces of garbage on the internet, so this doesn't surprise me.

You’ve never seen SRP in practice? This is honestly concerning.

You’ve never seen like a User class that only encapsulates fields and methods relating to a User abstraction?

I meant more as for non-trivial classes when people are deciding when to break up a class the "single responsibility" part is too loosely defined to the point where I've never seen people actually use it as a metric. I agree classes can grow too large the hard part is what rubric actually used for delineating it and just saying "single responsibility" really hasn't by itself been useful.

There has been plenty said about the topic. Have you read Clean Code? The Wikipedia page? The Pragmatic Programmer? The depth on the subject has been expanded far more than just “single responsibility”.

Here is Bob responding to OPs link: http://blog.cleancoder.com/uncle-bob/2020/10/18/Solid-Releva...

Stating:

“SRP) The Single Responsibility Principle.

Gather together the things that change for the same reasons. Separate things that change for different reasons.”

That’s a pretty clear delineation IMO.

@drooby yes we've all had to learn about it in class. "Single responsibility" has a definition but I've never seen a person have a good time defining the "single responsibility" part that well IRL when it comes to making/changing a class. Ironically, I think bob's later clarifications that the single responsibility refers to where a person/department would want change is much more usable https://blog.cleancoder.com/uncle-bob/2014/05/08/SingleRepon....

The want for change part is hard thing to define. Personally, I much prefer "separation of concerns" when deciding what to place where. I guess you could argue in some sense its around the same thing shrug.