@ashoat's [[ https://phab.comm.dev/D4450#inline-27739 | close reading ]] and this `git grep` command:
{F92895}
The command may be confusing to parse, so I plugged it into Regex101:
{F92898}
Essentially matches lines with `if`, then only one `[`, then zero or more characters in between the `[` and another only one of `]`.