in src/main.rs [1085:1094]
fn test_replacement_matches_search() {
let dir = create_test_files(&[("foo.txt", "foo")]);
let file_path = dir.path().join("foo.txt");
let regex = RegexBuilder::new("foo").build().unwrap();
let mut fm = Fastmod::new(true, false, false);
fm.present_and_apply_patches(®ex, "foofoo", &file_path, "foo".into())
.unwrap();
let contents = read_to_string(file_path).unwrap();
assert_eq!(contents, "foofoo");
}