Use ASDF version manager

At first, we did Ruby work, so we needed a ruby version manager.
Then we needed Node, so some of us added a node version manager.
Some of work with varying versions of Python, Elixir, Elm, etc.
ASDF lets us stop searching out solutions to the same problem in
each of these languges by supporting [plugins][1].

[1]: https://github.com/asdf-vm/asdf-plugins/tree/master/plugins

README.md

@@ -115,10 +115,9 @@ Testing tools:
 
 Programming languages, package managers, and configuration:
 
+* [ASDF] for managing programming language versions
 * [Bundler] for managing Ruby libraries
 * [Node.js] and [NPM], for running apps and installing JavaScript packages
-* [Rbenv] for managing versions of Ruby
-* [Ruby Build] for installing Rubies
 * [Ruby] stable for writing general-purpose code
 * [Yarn] for managing JavaScript packages
 
@@ -126,8 +125,7 @@ Programming languages, package managers, and configuration:
 [ImageMagick]: http://www.imagemagick.org/
 [Node.js]: http://nodejs.org/
 [NPM]: https://www.npmjs.org/
-[Rbenv]: https://github.com/sstephenson/rbenv
-[Ruby Build]: https://github.com/sstephenson/ruby-build
+[ASDF]: https://github.com/asdf-vm/asdf
 [Ruby]: https://www.ruby-lang.org/en/
 [Yarn]: https://yarnpkg.com/en/
 

mac

@@ -86,7 +86,6 @@ gem_install_or_update() {
     gem update "$@"
   else
     gem install "$@"
-    rbenv rehash
   fi
 }
 
@@ -114,6 +113,7 @@ brew bundle --file=- <<EOF
 tap "thoughtbot/formulae"
 tap "homebrew/services"
 tap "universal-ctags/universal-ctags"
+tap "caskroom/cask"
 
 # Unix
 brew "universal-ctags", args: ["HEAD"]
@@ -140,12 +140,11 @@ brew "imagemagick"
 # Testing
 brew "qt@5.5" if MacOS::Xcode.installed?
 
-# Programming languages and package managers
+# Programming language prerequisites and package managers
 brew "libyaml" # should come after openssl
-brew "node"
-brew "rbenv"
-brew "ruby-build"
+brew "coreutils"
 brew "yarn"
+cask "gpgtools"
 
 # Databases
 brew "postgres", restart_service: :changed
@@ -162,27 +161,48 @@ fancy_echo "Update heroku binary..."
 brew unlink heroku
 brew link --force heroku
 
-fancy_echo "Configuring Ruby ..."
-find_latest_ruby() {
-  rbenv install -l | grep -v - | tail -1 | sed -e 's/^ *//'
+fancy_echo "Configuring asdf version manager..."
+if [ ! -d "$HOME/.asdf" ]; then
+  git clone https://github.com/asdf-vm/asdf.git ~/.asdf --branch v0.3.0
+  append_to_zshrc "source $HOME/.asdf/asdf.sh" 1
+fi
+
+install_asdf_plugin() {
+  local name="$1"
+  local url="$2"
+
+  if ! asdf plugin-list | grep -Fq "$name"; then
+    asdf plugin-add "$name" "$url"
+  fi
 }
 
-ruby_version="$(find_latest_ruby)"
-# shellcheck disable=SC2016
-append_to_zshrc 'eval "$(rbenv init - --no-rehash)"' 1
-eval "$(rbenv init -)"
+# shellcheck disable=SC1090
+source "$HOME/.asdf/asdf.sh"
+install_asdf_plugin "ruby" "https://github.com/asdf-vm/asdf-ruby.git"
+install_asdf_plugin "nodejs" "https://github.com/asdf-vm/asdf-nodejs.git"
 
-if ! rbenv versions | grep -Fq "$ruby_version"; then
-  RUBY_CONFIGURE_OPTS=--with-openssl-dir=/usr/local/opt/openssl rbenv install -s "$ruby_version"
-fi
+install_asdf_language() {
+  local language="$1"
+  local version
+  version="$(asdf list-all "$language" | tail -1)"
 
-rbenv global "$ruby_version"
-rbenv shell "$ruby_version"
+  if ! asdf list "$language" | grep -Fq "$version"; then
+    asdf install "$language" "$version"
+    asdf global "$language" "$version"
+  fi
+}
+
+fancy_echo "Installing latest Ruby..."
+install_asdf_language "ruby"
 gem update --system
-gem_install_or_update 'bundler'
+gem_install_or_update "bundler"
 number_of_cores=$(sysctl -n hw.ncpu)
 bundle config --global jobs $((number_of_cores - 1))
 
+fancy_echo "Installing latest Node..."
+bash "$HOME/.asdf/plugins/nodejs/bin/import-release-team-keyring"
+install_asdf_language "nodejs"
+
 if [ -f "$HOME/.laptop.local" ]; then
   fancy_echo "Running your customizations from ~/.laptop.local ..."
   # shellcheck disable=SC1090