rust tdd: test/alphabet_position_test.rs

alphabet_position_test.rs

// test/alphabet_position_test.rs

use dev_challenge_47::alphabet_position;    // <-- we don't have this function yet

#[test]                                     // <-- how to define a test in rust
fn it_should_replace_the_a_with_1() {       // <-- we express the requirement as name
    let replaced = alphabet_position("a");
    assert_eq!(replaced, "1");              // <-- we assert that the both are equal
}