Brewery is a tool to simply dump a Brewfile.
$ git clone https://github.com/ada-u/brewery ~/src/brewery
$ cd ~/src/brewery
$ ./install.sh
init dumps new Brewfile in current directory, but it does not overwrite existing Brewfile.
$ brewery init
update creates or overwrites Brewfile in current direcoty.
$ brewery update
$ brew bundle
$ brewery update
$ cat Brewfile
# Update homebrew
update
# Upgrade already-installed packages
upgrade
# Add repositories
tap homebrew/binary
tap homebrew/versions
tap phinze/cask
# Install brew-cask
tap phinze/homebrew-cask
install brew-cask
# Install brew-packages
install ansible
install tig
install tmux
install vim
install watch
install wget
# Install cask-packages
cask install wireshark
# Remove outdated version
cleanup