Script that suffixes commit message with the issue ID taken from a branch name.

prepare-commit-msg

#!/bin/sh
. "$(dirname "$0")/_/husky.sh"

COMMIT_MSG_FILE=$1
COMMIT_SOURCE=$2

BRANCH_NAME=$(git rev-parse --abbrev-ref HEAD 2>/dev/null)
CHORE_BRANCH_REGEX='^chore-.+$'
VALID_BRANCH_REGEX='^issue-[0-9]+-.+$'
COMMIT_MESSAGE=$(<$COMMIT_MSG_FILE)

# Exit without error if it's not a local commit or if it's a chore branch or it's a rebase
if [ "$COMMIT_SOURCE" != "message" ] || [[ $BRANCH_NAME =~ $CHORE_BRANCH_REGEX ]] || [ "$BRANCH_NAME" = "HEAD" ]; then
    exit 0
fi

# Exit with error when the branch name is invalid
if [[ ! $BRANCH_NAME =~ $VALID_BRANCH_REGEX ]]; then
    echo "Branch names in this project must adhere to this contract: $VALID_BRANCH_REGEX. You should rename your branch to a valid name and try again."
    exit 1
fi

if [ ! -z "$BRANCH_NAME" ]; then

  SUFFIX_PATTERN='issue-([0-9]+)'

  [[ $BRANCH_NAME =~ $SUFFIX_PATTERN ]]

  SUFFIX=${BASH_REMATCH[1]}
  VALID_MESSAGE_REGEX="^.+ \(#$SUFFIX\)$"

  # Prefix branch name with issue ID if not already prefixed
  if [[ -n "$SUFFIX" ]] && [[ ! $COMMIT_MESSAGE =~ $VALID_MESSAGE_REGEX ]]; then
    echo "$COMMIT_MESSAGE (#$SUFFIX)" > "$COMMIT_MSG_FILE"
  fi
fi