testadder/
lib.rs

1pub fn add_two(a: i32) -> i32 {
2    internal_adder(a, 2)
3}
4
5fn internal_adder(a: i32, b: i32) -> i32 {
6    a + b
7}
8
9#[cfg(test)]
10mod tests {
11    use super::*;
12
13    #[test]
14    fn internal() {
15        assert_eq!(4, internal_adder(2, 2));
16    }
17}