git-switch

#!/bin/sh

# Check if params are sufficient enough to go ahead.
checkoutBranchParam=$1
# If user didn't specify branch to checkout to, stop and show error.
test -z $checkoutBranchParam && echo "ERROR: Please provide the destination branch to checkout to." 1>&2 && exit 1

# Find which is your current branch
if currentBranch=$(git symbolic-ref --short -q HEAD)
then
  echo On branch $currentBranch
  echo "Stash changes."

  # Stash current changes
  git stash
  
  # If local branch exist or not.
  if [ $(git branch --list $checkoutBranchParam + | wc -l) == "1" ]
  then
    echo "Branch name $checkoutBranchParam already exists. Switch to it."
    git checkout $checkoutBranchParam
  else 
    echo "Branch name $checkoutBranchParam does not exists. Create the branch and switch."
    git checkout -b $checkoutBranchParam
  fi

  # Apply the stashed changes
  git stash apply

  echo Successfully checked out the branch $checkoutBranchParam!
else
  echo ERROR: Cannot find the current branch!
fi