example.rs

use std::io::println;

fn is_three(num: int) -> bool {
  num % 3 == 0
}

fn is_five(num: int) -> bool {
  num % 5 == 0
}

fn is_fifteen(num: int) -> bool {
  num % 15 == 0
}

#[test]
fn test_is_three_with_not_three() {
  if is_three(1) {
    fail!("One is not three");
  }
}

#[test]
fn test_is_three_with_three() {
  if !is_three(3) {
    fail!("Three should be three");
  }
}

#[test]
fn test_is_five_with_not_five() {
  if is_five(1) {
    fail!("One is not five");
  }
}

#[test]
fn test_is_five_with_five() {
  if !is_five(5) {
    fail!("Five should be five");
  }
}

#[test]
fn test_is_fifteen_with_not_fifteen() {
  if is_fifteen(1) {
    fail!("One is not fifteen");
  }
}

#[test]
fn test_is_fifteen_with_fifteen() {
  if !is_fifteen(15) {
    fail!("Fifteen should be fifteen");
  }
}

fn main() {
  for num in range(1i, 101) {
    let answer =
      if is_fifteen(num) {
        "FizzBuzz".to_str()
      } else if is_three(num) {
        "Fizz".to_str()
      } else if is_five(num) {
        "Buzz".to_str()
      } else {
        num.to_str()
      };

    println(answer.as_slice());
  }
}