simple Git workflow script

feature.sh

# Workflow:
#  
#   1. feature start 000-new-feature
#   2. git commit -m "here's my new feature"
#   3. feature update
#   4. git commit -m "here's some tests"
#   5. feature diff
#   6. feature finish 000-new-feature
#   7. git push origin master

function feature {
  usage="feature [start|finish|update|log|diff] <branch>"
  if [ -z "$1" ]; then echo $usage; return 1; fi
  case "$1" in
    st*)
      if [ -z "$2" ]; then echo $usage; return 1; fi
      git checkout master
      git pull --rebase origin master || return 1
      git checkout -b $2
      ;;
    fin*)
      if [ -z "$2" ]; then echo $usage; return 1; fi
      git checkout $2 || return 1
      git pull --rebase origin master || return 1
      git checkout master
      git pull --rebase origin master || return 1
      git merge --squash $2 || return 1
      git commit || return 1
      git branch -D $2
      ;;
    up*)
      git pull --rebase origin master
      ;;
    log) ;&
    diff)
      if [ -n "$2" ]; then git checkout $2; fi
      git $1 origin/master..HEAD
      ;;
    *)
      echo $usage
      return 1
      ;;
  esac
  return 0
}