make buf() to respect file attributes on file backup

plugins/available/base.plugin.bash

@@ -213,5 +213,5 @@ function buf ()
     group 'base'
     local filename=$1
     local filetime=$(date +%Y%m%d_%H%M%S)
-    cp "${filename}" "${filename}_${filetime}"
+    cp -a "${filename}" "${filename}_${filetime}"
 }

test/plugins/base.plugin.bats

@@ -34,3 +34,11 @@ load ../../plugins/available/base.plugin
   assert_success
   [[ $output == l? ]]
 }
+
+@test 'plugins base: buf()' {
+  mkdir -p $BASH_IT_ROOT
+  declare -r file="${BASH_IT_ROOT}/file"
+  touch $file
+  run buf $file
+  [[ -e ${file}_$(date +%Y%m%d_%H%M%S) ]]
+}