grrsjstitch/
lib.rs

1pub fn find_matches(content: &str, pattern: &str, mut writer: impl std::io::Write) {
2    for line in content.lines() {
3        if line.contains(pattern) {
4            writeln!(writer, "{}", line).expect("Could not write to writer");
5        }
6    }
7}
8
9#[test]
10fn find_a_match() {
11    let mut result = Vec::new();
12    find_matches("lorem ipsum\ndolor sit amet", "lorem", &mut result);
13    assert_eq!(result, b"lorem ipsum\n")
14}