testingrust

How do you test functions that return Result?

I have a function that returns Result<(), MyError> where: 

enum MyError {Error1, Error2}

I am currently doing the following:

#[test]
fn test_result_function() {
    assert_eq!((), result_function().unwrap());
}

This works but seems awkward. At first I was going to do:

assert!(result_function().is_ok());

but when it wasn't ok, the test result didn't give the error anywhere. How should I go about testing this function?

Solution

  • How about 

    assert_eq!(Ok(()), result_function());

    this needs 

    #[derive(PartialEq,Debug)]
enum MyError{Error1, Error2}

    to work and will tell you 

    `(left == right)` (left: `Ok(())`, right: `Err(Error1)`)'

    when testing when your result_function returns an Error1 when the test says it should return Ok(()).