Add test for one-character string
@@ -117,6 +117,7 @@ fn dedup_by() {
#[test]
fn all_equal() {
assert!("".chars().all_equal());
+ assert!("A".chars().all_equal());
assert!(!"AABBCCC".chars().all_equal());
assert!("AAAAAAA".chars().all_equal());
for (_key, mut sub) in &"AABBCCC".chars().group_by(|&x| x) {
