git/hooks/prepare-commit-msg (auto prefix ticketID)

prepare-commit-msg

#!/bin/bash

# Idea is mine (@a_c_m), code it ChatGPT-4, don't forget to `chmod +x .git/hooks/prepare-commit-msg`

# Automatically adds the ticket ID to the commit message, or warns how to do it.
# Get the current branch name
BRANCH_NAME=$(git symbolic-ref --short HEAD)

# Parse arguments
COMMIT_MSG_FILE="$1"
COMMIT_SOURCE="$2"
SHA1="$3"

COMMIT_MSG=$(cat "$COMMIT_MSG_FILE")

# Check if commit message starts with a ticket ID
if ! [[ "$COMMIT_MSG" =~ ^[A-Z]+-[0-9]+ ]]; then
  # If not, check if branch name starts with a ticket ID
  if [[ "$BRANCH_NAME" =~ ^[A-Z]+-[0-9]+ ]]; then
    # If yes, extract the ticket ID and prefix it to the commit message
    TICKET_ID=$(echo "$BRANCH_NAME" | grep -o '^[A-Z]\+-[0-9]')
    COMMIT_MSG="$TICKET_ID: $COMMIT_MSG"
  else
    # If not, print a warning and instructions to amend the commit message
    echo "WARNING: Commit message does not start with a ticket ID (e.g. 'TEST-123: ')."
    echo "You can re-commit to amend your commit message, use: git commit --amend -m 'TEST-123: old message'"
  fi
fi

# Write the possibly modified commit message back to the file.
echo "$COMMIT_MSG" > "$COMMIT_MSG_FILE"