git-worktree-create

#!/usr/bin/env bash

function main {
  local BRANCH_NAME="${1:-}"

  if [ -z "$BRANCH_NAME" ]; then
    print-usage
    exit 1
  fi

  if [ "$BRANCH_NAME" = "-h" ] || [ "$BRANCH_NAME" = "--help" ]; then
    print-usage
    exit 0
  fi

  local git_dir
  if [ -d ".git" ]; then
    git_dir="$(pwd)"
  else
    git_dir="$(dirname "$(ls -d ./*/.git/)" | head -n1)"
  fi

  if [ -z "$git_dir" ]; then
    echo "No git directory found in current or sub-directories"
    echo "Please run this script from a git directory or directly above one"
    exit 1
  fi

  local create_dir
  create_dir="$(realpath "$git_dir/..")/$BRANCH_NAME"

  echo "Creating new git workdir in $create_dir"

  mkdir -p "$create_dir"

  cd "$git_dir" || fail "Could not cd to $create_dir"

  if git rev-parse --verify "$BRANCH_NAME" >/dev/null 2>&1; then
    echo "Branch '$BRANCH_NAME' already exists"
  else
    echo "Creating branch '$BRANCH_NAME'"
    git branch "$BRANCH_NAME"
  fi

  git worktree add "$create_dir" "$BRANCH_NAME"

  echo "Workdir created"

  echo "Adding upstream remote if applicable"
  cd "$create_dir" || fail "Could not cd to $create_dir"
  setup-upstream-remote "$BRANCH_NAME"

  echo "To switch to this workdir, run:"
  echo "  cd $(realpath --relative-to="$PWD" "$create_dir")"
}

function setup-upstream-remote {
  local BRANCH_NAME="${1}"

  git fetch --all

  git branch --set-upstream-to=origin/"$BRANCH_NAME" "$BRANCH_NAME" &>/dev/null
  local result="$?"

  if [ "$result" -ne 0 ]; then
    echo "Upstream remote seemingly does not exist"
    return
  fi

  echo "Upstream remote set, pulling commits"
  git pull
  echo "Synced with upstream"
}

function fail {
  echo "Error: $*" >&2
  exit 1
}

function print-usage {
  local script_name
  script_name="$(basename "$0")"

  printf "%s - Create a git workdir, but simpler\n" "$script_name"
  echo "Usage:"
  printf "  %s <branch-name>\n" "$script_name"
}

set -uo pipefail
if [ -n "${DEBUG:-}" ]; then
  set -x
fi

main "$@"