# Empty constraints: `before ""` is (?<=) — a no-op; `not_before ""`
# and `not_after ""` are (?<!)/(?!) — never true, disabling the rule.
system "T:rs-empty-constraints:1" {
stage main {
sequence {
sub { from "a" to "X" before "" }
sub { from "a" to "Y" not_before "" }
sub { from "a" to "Z" not_after "" }
}
}
tests {
"aa" -> "XX"
}
}