我在导入add_two.rs中定义的公共add_two函数时遇到了麻烦。这是我的项目结构。

Cargo.toml
src/
    main.rs
    add_two.rs
tests/
    integration_test.rs

下面是我的main.rs文件，它定义了main函数。

//binary crate: it contains main function

pub mod add_two; 

#[cfg(test)]
mod tests {
    use crate::add_two::add_two; 

    #[test]
    fn add_two_and_two(){
        assert_eq!(4, add_two(2)); 
    }
    #[test]
    fn add_three_and_two(){
        assert_eq!(5, add_two(3)); 
    }
    #[test]
    fn one_hundred(){
        assert_eq!(102, add_two(100)); 
    }
    #[test]
    #[ignore]
    fn test_we_want_to_ignore() {
        //snippet of code that takes too much processing time! 
    }
}

fn main() {

}

这是我的add_two.rs文件。

//library crate 

pub fn add_two(a: i32) -> i32 {
    a + 2
}

下面是我的integration_test.rs文件。

use crate::add_two::add_two; 

#[test]
fn add_two_with_two() {
    assert_eq!(add_two(2), 4); 
}

这是我的货物，toml文件.

[package]
name = "tutorial1"
version = "0.1.0"
edition = "2021"

# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

[dependencies]