rustlings中文指南Appearance
测试3：exercises/tests/tests3.rs
题目
rust
// tests3.rs
//
// This test isn't testing our function -- make it do that in such a way that
// the test passes. Then write a second test that tests whether we get the
// result we expect to get when we call `is_even(5)`.
//
// Execute `rustlings hint tests3` or use the `hint` watch subcommand for a
// hint.
// I AM NOT DONE
pub fn is_even(num: i32) -> bool {
num % 2 == 0
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn is_true_when_even() {
assert!();
}
#[test]
fn is_false_when_odd() {
assert!();
}
}这个题目不是考函数的，而是让它的单元测试顺利通过。
编写的第二个单元测试用来测试我们调用is_even(5)的时候是否是我们期望的结果。
题目解析
rust
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn is_true_when_even() {
assert!();
assert!(is_even(2));
}
#[test]
fn is_false_when_odd() {
assert!();
assert!(!is_even(5));
}
}为了更清楚，也可以使用下面这种方式：
rust
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn is_true_when_even() {
assert!();
assert!(is_even(2) == true);
}
#[test]
fn is_false_when_odd() {
assert!();
assert!(is_even(5) == false);
}
}