GitHub update and force-push only changed files from previous commit (add to your bash profile and run as `gup`)

gup.bash

# Git Update-and-Push (gup)
# Amends the last commit with any changes to files included in that commit and force-pushes the updated commit.
# Usage:
#   gitup            # Amend last commit with changes to files in that commit and force-push
#   gitup -s         # Show status of files in last commit without amending; 🔥 indicates changes
gup() {
  # Check for flags
  local status_only=false

  if [[ "$1" == "-s" || "$1" == "--status" ]]; then
    status_only=true
  fi

  # Show status and exit if requested
  if [[ "$status_only" == true ]]; then
    echo
    git diff-tree --no-commit-id --name-only -r HEAD | while read -r file; do
      if git diff --name-only | grep -q "^${file}$"; then
        echo "🔥 $file"
      else
        echo "  $file"
      fi
    done
    echo
    return 0
  fi

  # Get files from last commit and stage them if modified
  git diff-tree --no-commit-id --name-only -r HEAD | xargs -r git add --

  # Skip if nothing was staged
  if git diff --cached --quiet; then
    echo "No changes to amend from last commit"
    return 1
  fi

  # Show what will be amended
  echo
  echo "Files to amend:"
  git diff --cached --name-only
  echo

  # Amend and force push with lease
  git commit --amend --no-edit && git push --force-with-lease
}