restaurant/
lib.rs

1pub fn main() {
2  println!("This is a library");
3}
4
5pub fn add_two(a: i32) -> i32 {
6  internal_adder(a, 2)
7}
8
9fn internal_adder(a: i32, b: i32) -> i32 {
10  a + b
11}
12
13#[cfg(test)]
14mod tests {
15  use super::*;
16
17  #[test]
18  fn internal() {
19      assert_eq!(4, internal_adder(2, 2));
20  }
21}