next_fibonacci 0.1.0

/// Calculate the next number in the fibonacci sequence
///
/// # Examples
///
/// ```
/// let n = 15;
///
/// let result = next_fibonacci::fibonacci(15);
/// 
/// assert_eq!(27, result);
///

pub fn fibonacci(n: u32) -> u32 {
    if n == 0 || n == 1 {
        n
    } else {
        (n - 1) + (n - 2)
    }
}



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

    #[test]
    fn fib_zero() {
        let result = fibonacci(0);
        assert_eq!(result, 0);
    }
    #[test]
    fn fib_one() {
        let result = fibonacci(1);
        assert_eq!(result, 1);
    }
    #[test]
    fn fib_other() {
        let result = fibonacci(15);
        assert_eq!(result, 27);
    }
}