install_xcode.sh

- Pluginfile

gem 'xcode-install'

- Fastfile

platform :ios do
  desc "Xcode install"
  lane :install_xcode do
    xcode_install(
      version: "#{ENV['XCODE_VERSION']}",
      username: "some@apple.id"
    )
  end
end

- install_xcode.sh

export FASTLANE_SESSION="a_valid_session"
export XCODE_VERSION="13.3.1"
# Installs Xcode
bundle exec fastlane install_xcode
# Changes CLT to new Xcode
sudo xcode-select -s /Applications/Xcode-$XCODE_VERSION.app
# Validates Xcode version
/usr/libexec/PlistBuddy -c "Print CFBundleShortVersionString" /Applications/Xcode-$XCODE_VERSION.app/Contents/Info.plist
# Validates CLT path
xcode-select -p
# Validates swift version
swift --version