# Matchers ## contain_match Test if an array contains a matching element, which is identified by a regular expression. ```ruby describe audit_daemon_rules do its("LIST_RULES") {should contain_match(/^exit,always arch=.* key=time-change syscall=adjtimex,settimeofday/) } end ``` ## contain_duplicates Test if a list contains duplicate elements: ```ruby describe etc_group do its(:gids) { should_not contain_duplicates } end ```