Testing Patterns

Patterns สำหรับ testing ใน Rust

Basic Test Structure

// Unit test
fn add(a: i32, b: i32) -> i32 {
    a + b
}

fn divide(a: i32, b: i32) -> Result<i32, String> {
    if b == 0 {
        Err("Division by zero".to_string())
    } else {
        Ok(a / b)
    }
}

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

    #[test]
    fn test_add() {
        assert_eq!(add(2, 3), 5);
    }

    #[test]
    fn test_add_negative() {
        assert_eq!(add(-1, 1), 0);
    }

    #[test]
    fn test_divide_success() {
        assert_eq!(divide(10, 2), Ok(5));
    }

    #[test]
    fn test_divide_by_zero() {
        assert!(divide(10, 0).is_err());
    }

    #[test]
    #[should_panic]
    fn test_panic() {
        panic!("This test should panic");
    }

    #[test]
    #[should_panic(expected = "specific")]
    fn test_specific_panic() {
        panic!("specific error message");
    }

    #[test]
    #[ignore]
    fn expensive_test() {
        // Run with: cargo test -- --ignored
        std::thread::sleep(std::time::Duration::from_secs(10));
    }
}

fn main() {
    println!("add(2, 3) = {}", add(2, 3));
    println!("divide(10, 2) = {:?}", divide(10, 2));
}