container: hledger-flow: lib_preprocess: add custom delim when testing

given header column(s).

container/src/hledger-flow/lib/lib_preprocess.bash

@@ -64,10 +64,16 @@ echo -e "    \e[32m│     └─\e[37;2m ${global_in_filename}\e[0m"
 function lib_preprocess::test_header()
 {
   local _column="$1"
+
   local _header
   _header="$(lib_preprocess::__sanitize_header $2)"
-  # TODO: add custom delim
-  [[ "$_header" =~ (^"${_column}"$|^"${_column}",|,"${_column}",|,"${_column}"$) ]] && return 0 || return 2
+
+  local _delim="$3"
+  [ -z "$_delim" ] && _delim=","
+
+  # TODO: consolidate regexp
+  [[ "$_header" =~ (^"${_column}"$|^"${_column}${_delim}"|"${_delim}${_column}${_delim}"|"${_delim}${_column}"$) ]] \
+    && return 0 || return 2
 }
 
 # Assert header in given CSV header