Conventional commit git hook; enforces the format of commit messages.

prepare-commit-msg

#!/bin/bash
set -euo pipefail
COMMIT_MESSAGE="$(head -n1 "$1")"
echo "$COMMIT_MESSAGE" | gawk '
BEGIN{
  types["feat"]=0;
  types["fix"]=0;
  types["doc"]=0;
  types["text"]=0;
  types["style"]=0;
  types["refactor"]=0;
  types["process"]=0;
  types["revert"]=0;
  issue_names["#"]=0;
}
/Merge branch/{exit 0}
{match($0, /^([[:alnum:]]+) ([[:alpha:]#]+)[0-9]+[(][^]]*[)]: .+/, array);
if (RLENGTH == -1) {print "Invalid commit message format:", $0; print "      TYPE ISSUE(SCOPE): MESSAGE\ne.g.  feat i33(front end): Made a popup" ; exit(1)};
if (!(array[1] in types)) { print "Invalid type:", array[1]; print "Valid types:"; for (key in types) print " ", key; exit 1 }
if (!(array[2] in issue_names)) { print "Invalid issue name:", array[2]; exit 1 }
}'