All words you can type in one row

one_row.rs

static KEYBOARD_ROWS: [&str; 3] = ["qwertyuiop", "asdfghjkl", "zxcvbnm"];

fn main() {
    let words = vec!["candy", "fart", "pop", "Zelda", "flag", "typewriter"];
    let res = one_row(words);
    println!("{:?}", res);
}

fn one_row(words: Vec<&str>) -> Vec<&str> {
    return words
        .into_iter()
        .filter(|word| {
            KEYBOARD_ROWS
                .iter()
                .find(|row| {
                    word.to_lowercase()
                        .chars()
                        .all(|input_char| row.contains(input_char))
                })
                .is_some()
        })
        .collect();
}

#[cfg(test)]

mod tests {

    use super::*;

    #[test]
    fn test_one_row() {
        assert_eq!(
            vec!["pop", "flag", "typewriter"],
            one_row(vec!["candy", "fart", "pop", "Zelda", "flag", "typewriter"])
        );
    }
}