use RosalindError;
use RosalindError::UnknownNucleotide;
pub fn reverse_complement_dna(dna: &str) -> Result<String, RosalindError> {
let mut complement_dna = String::new();
for nucleotide in dna.chars().rev() {
match nucleotide {
'A' => complement_dna.push('T'),
'C' => complement_dna.push('G'),
'G' => complement_dna.push('C'),
'T' => complement_dna.push('A'),
'\n' => continue,
_ => return Err(UnknownNucleotide(nucleotide))
}
}
Ok(complement_dna)
}
#[cfg(test)]
mod tests {
use super::reverse_complement_dna;
use super::super::RosalindError::UnknownNucleotide;
#[test]
fn it_should_return_error_when_unknown_nucleotid_found() {
assert_eq!(reverse_complement_dna("Z").unwrap_err(), UnknownNucleotide('Z'));
}
#[test]
fn it_should_reverse_complement_dna() {
let dna = "AAAACCCGGT";
assert_eq!(reverse_complement_dna(dna).unwrap(), "ACCGGGTTTT");
}
#[test]
fn it_should_skip_new_line_symbol() {
assert_eq!(reverse_complement_dna("\n").unwrap(), "");
}
}