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What's the procedure for mocking structs? (programming.dev)
submitted 1 year ago by nerdblood@programming.dev to c/rust@programming.dev
9 comments fedilink hide all child comments

I know there's mockall which seems to be geared towards implementation methods and traits, but I'm wondering about just structs with non-function properties.

In my tests, I want to define initialized structs with values. It works fine to just do it like I normally would in code, but I'm wondering if there's more to it than that. Like if I have a cat struct:

struct Cat { name : String } `

#[cfg(test)] pub mod test { use super::Cat; fn test_create_cat() -> Cat { Cat { name. : String::from("Fred") }; }

That's fine, but should I be doing it differently? What about mockall, is it not meant for structs with properties?

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[-] nerdblood@programming.dev 2 points 1 year ago

This is a great answer, thanks. I'll have to look more into conditional compilation. That's new to me.

[-] TehPers@beehaw.org 1 points 1 year ago

A few days later, but keep in mind that if you write your tests in the module you declare your structs, you'll have access to its "private" (non-pub) members since those are technically module scoped (default scope is pub(self)).

pub struct Cat {
    name: String,
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn create_cat() {
        let cat = Cat {
            name: "fluffy".into(),
        };
    }
}

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this post was submitted on 04 Aug 2023
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