You're right, I probably should have added a unit test. I added one in a branch of ongoing work. I don't always add unit tests, but in this case, it was pretty

You're right, I probably should have added a unit test. I added one in a branch of ongoing work. I don't always add unit tests, but in this case, it was pretty easy to. (FWIW, this is in the grep-regex crate, not the regex crate. The grep-regex crate is a glue layer between regex and ripgrep that adds in a bunch of line-oriented optimizations.) > While repeating yourself exactly once isn't automatically a bad sign, it smells suspicious. It seems like there would be a lot of tests that ought to behave exactly the same with or without --mmap and so maybe that's a pattern worth extracting. Quite possibly. Not a bad idea. I already do that in the tests for PCRE2. Most tests are run with both the default regex engine and with PCRE2. (There are some tests that have intended behavioral differences with mmap enabled, but those can be handled on a case-by-case basis.)