Prepend the branch name to your commit message automatically

prepare-commit-msg.sh

#!/bin/bash

# Produces output like "[my-branch] My Commit" or "[TICKET] Add foo and bar"
# Use "BRANCHES_TO_SKIP" if you don't want to prepend 
# the branch name onto commits on a certain branch

if [ -z "$BRANCHES_TO_SKIP" ]; then
 BRANCHES_TO_SKIP=(main develop my-special-branch)
fi

BRANCH_NAME=$(git symbolic-ref - short HEAD)
BRANCH_NAME="${BRANCH_NAME##*/}"
BRANCH_EXCLUDED=$(printf "%s\n" "${BRANCHES_TO_SKIP[@]}" | grep -c "^$BRANCH_NAME$")
BRANCH_IN_COMMIT=$(grep -c "\[$BRANCH_NAME\]" $1)

if [ -n "$BRANCH_NAME" ] && ! [[ $BRANCH_EXCLUDED -eq 1 ]] && ! [[ $BRANCH_IN_COMMIT -ge 1 ]]; then
 sed -i.bak -e "1s/^/$BRANCH_NAME /" $1
fi

# This script is widely shared online, so I couldn't find the original author
# There are lots of variants, so if you need some extra logic, take a look!