Unit tests and "raw pointer"

[MMK]

I recently read chapter 12 of the book and decided to create my own implementation of the program, my program is a shell over the aho_corasick crate, which stores, updates and saves data from the search file in it. In my unit test for the AhoCorasickBuilder getter, I encountered a problem because AhoCorasickBuilder does not implement PartialEq. ChatGPT advised me to convert to "raw pointer"(*const _), whether it is correct to write such unit tests for the getter.:

#[test]
fn get_builder(){
    let mut builder=AhoCorasickBuilder::new();
    builder.auto_configure(&["some", "hay"]);
    let  grep = MiniGrep::new(["some", "hay"], "some haystack", None);
    assert_eq!(grep.get_builder() as *const _,&grep.corasick_builder as *const _);
}

or

#[test]
fn get_mut_matches(){
    let mut grep = MiniGrep::new(["some", "hay"], "some haystack", None);
assert_eq!(grep.get_mut_matches() as *const _,&mut grep.matches as *const _)
}

And how is it better to write like that?:

#[test]
fn get_matches(){
    let grep = MiniGrep::new(["some", "hay"], "some haystack", None);
    assert_eq!(&grep.matches,grep.get_matches())
}

or:

#[test]
fn get_matches(){
    let grep = MiniGrep::new(["some", "hay"], "some haystack", None);
    assert_eq!(grep.matches.as_slice() as *const _ ,grep.get_matches() as *const _)
}

[semicoleon]

You're just comparing the pointer values i.e. the memory addresses. That isn't going to do a meaningful equality test on the actual data inside the builder.

[MMK]

Well,yes,my goal was just to check that the getter returns a link to this field,but I would like to know if it makes sense to write such tests?

[semicoleon]

Ahh I see, no I don't think there's much value in that kind of a test. I'm sure there are some scenarios where ensuring a function returns a specific field might be important, but they'd be extremely niche. I would focus on writing tests for the parts of your code that are more closer to the higher level goals of your project

[MMK]

thank you