Refactor commit trailer regex

Refactor commit trailer regex by renaming default_trailers_by to
DEFAULT_TRAILERS_BY to follow the naming convention for global
variables.Then refine build_commit_trailer_regex by reusing the array.

Co-authored-by: EricccTaiwan <[email protected]>
Change-Id: I7c7e9367f59a6da0ff84605904d08343ad558f42

Author: charliechiou

scripts/commit-msg.hook

@@ -130,6 +130,16 @@ get_all_match_positions() {
   done <<< "$targets"
 }
 
+DEFAULT_TRAILERS_BY=(
+  'Signed-off-by'
+  'Reviewed-by'
+  'Co-authored-by'
+  'Acked-by'
+  'Suggested-by'
+  'Tested-by'
+  'Reported-by'
+)
+
 # Build regex for detecting commit trailers.
 build_commit_trailer_regex() {
   local -a keys specials standalones trailers
@@ -145,21 +155,16 @@ build_commit_trailer_regex() {
     'Signed-off-by' 'Suggested-by' 'Tested-by'
   )
 
+  trailers_test=(
+    'CC' 'Change-Id' 'Closes'
+    "${DEFAULT_TRAILERS_BY[@]}"
+  )
   # Standalone keys (those that do not require a value).
   standalones=(
     '(Doc|Upgrade|Security)Impact'
     "Git-Dch[$separators] (Ignore|Short|Full)"
   )
 
-  default_trailers_by=(
-    'Signed-off-by'
-    'Reviewed-by'
-    'Co-authored-by'
-    'Acked-by'
-    'Suggested-by'
-    'Tested-by'
-    'Reported-by'
-  )
 
   # Read custom trailer keys from git config and add them either to specials or trailers.
   # This loop reads lines matching 'trailer.*.key'.
@@ -181,7 +186,7 @@ build_commit_trailer_regex() {
   done < <(git config --get-regexp 'trailer.*.key')
 
   if [[ ${#trailers_by[@]} -eq 0 ]]; then
-    trailers_by=("${default_trailers_by[@]}")
+    trailers_by=("${DEFAULT_TRAILERS_BY[@]}")
   fi
 
   # Possible trailers :