.
Please, take the code it has produced and integrate it into the original function. All it does is replace the range call. That's it. It has absolutely and totally failed at the given task whilst outputting plausible garbage about why it has succeeded.
How the hell do I test a print function? I take the print function and match it with what? It has no output so how can I test it printed the correct thing? I can't.
I can test a list. I just match it with another list. Making your code unit testable is about segregating IO from logic. Write pure logic where all functions have inputs and outputs and those things can be tested. Your io prints should be small because all functions that do io cannot be fully tested.
IO is pollution. Any output to IO is the program exiting the logical mathematical universe of the program and that output can be verified only by an external entity. Either your eyes for stdout or another process or files or a bunch of other ways.
Unit tests are about internal local tests that touch local functionality and logic. If you want something unit testable it needs a local output and an input and it shouldn't rely on io in it's data path.
I think your complaint here is an example of chatGPT superiority. It understood something you didn't. Well now you know.
Removing the print function from the logic and returning the data is 100 percent the correct move. Do you understand?
Of course you can make the function with a print statement more unit testable without completely changing it's semantics!
You pass in an outputstream and use that as the target for print.
Then your unit test can create its own stream and test the content of the stream whilst production code can pass in standard out.
That way you don't completely change the semantic meaning of the code.
And once again that GPT function is useless. It is identical to list(range()) and it doesn't do what the first function does. Anyone can make anything more unit testable if it doesn't have to do the same thing.
The function is still touching io. You gonna test it with another function that touches io? That defeats the point of the definition of unit testability.
> and doesn't do what the first function does.
Are you serious? You mock your output streams with hacky monkey patching your function ALSO stops doing what it originally does. It's essentially black magic globals that mutate your program... very bad practice.
Chatgpt here just didn't write the obvious io component of the code because it would be freaking pedantic. The full code would include a function that prints lists composed with a function that produces lists. The composition allows part of the program to be testable while leaving the io part of it not testable. For the original program NONE of it was testable.
Your Monkey patching here would be replaced by different io functions. You want to change the output stream? then you change the IO function. Compose the list producer with another IO function. Play type Tetris and you can recompose your list producing function with all kinds of modular io. The point it you separated the core logic away from IO thereby making it more modular and more testable.
None of the io functions are testable via unit tests, that is the point. That is the definition of the most basic form of testing... Unit tests.
You literally HAVE to change your code in order to make it unit testable. If your code is throwing shit to io and retrieving values from io then none of your code is unit testable. You're at the integration test level and at this level things become hacky and more complicated. Your tests not have external dependencies like state, the operating system and you have to run hacks like your monkey patch.
Where ever you work or whatever you've been doing if you haven't been doing what I described then you (and your work buddies) haven't been testing your code via unit tests.
That's fine, whatever works bro. But chatGPT knows the common parlance for testing and unit testing, and it did exactly the correct thing.
Your interpretation of what testing is the thing that is strange and off here.
Output formatting touches io. In this case it is no longer a unit test that touches these things. Unit tests by definition test ONLY internal logic and transformations.
It is literally the definition of unit tests.
When you test things like stdout that becomes an integration test and Not a unit test. It requires some external thing or some global black magic monkey patch that changes what print does to do integration testing.
(Btw making print formatting unit testable means segregating the formatting from the print. Produce the string first, test that, then print, because print can never be unit tested by definition)
Typically programmers segregate these levels of testing because unit tests are easier to write. But to write unit tests your code has to be written in a way to cater to it. Often this style of coding actually improves your code it makes it much more modular. The reason is because pure functions that output data can be composed with all kinds of io functions. You can move it all over the place and to different platforms with different forms of IO. Print has no meaning in certain embedded systems so it can't be moved... By segregating the logic out it makes it so I can move the logic without the io baggage.
Chatgpt 100 percent gets the difference that's why it did what it did. I think you and the OP don't fully understand the meaning of unit testing.
Don't take this the wrong way, but just because you don't know this doesn't say anything about your skills as a programmer. But just recognize that this concept is basic and is pretty much something universal among testing.
By definition a unit test can only test functions that return data. So there's no other option here.
