[rb] keep rbenv and RubyMine and bazel in sync with ruby version

Rakefile

@@ -747,9 +747,35 @@ namespace :rb do
 
   desc 'Update generated Ruby files for local development'
   task :local_dev do
+    puts 'installing ruby, this may take a minute'
     Bazel.execute('build', [], '@bundle//:bundle')
     Rake::Task['rb:build'].invoke
     Rake::Task['grid'].invoke
+    Bazel.execute('build', [], '@bundle//bin:rubocop')
+    manage_selenium_ruby!
+  end
+
+  def manage_selenium_ruby!
+    label = 'selenium-ruby'
+
+    rbenv_path = `command -v rbenv`.strip
+    rbenv_root = `#{rbenv_path} root`.strip
+    dest = File.join(rbenv_root, 'versions', label)
+    return if File.symlink?(dest)
+
+    rb_dir = File.join(Dir.pwd, 'rb')
+    bazel_bin  = File.expand_path('../bazel-selenium/external/rules_ruby++ruby+ruby/dist/bin', rb_dir)
+    bazel_dist = File.dirname(bazel_bin)
+    FileUtils.ln_s(bazel_dist, dest)
+    system(rbenv_path, 'rehash')
+
+    Dir.chdir(rb_dir) do
+      system('direnv allow')
+      system('direnv reload')
+      system({ "RBENV_VERSION" => label }, 'bundle', 'install')
+    end
+  rescue StandardError => e
+    puts "Unable to set Bazel Selenium as Default: #{e.message}"
   end
 
   desc 'Push Ruby gems to rubygems'

rb/.envrc

@@ -0,0 +1,18 @@
+# Local Ruby environment for Selenium's Bazel-built Ruby
+# Safe to check in — only activates if the symlink already exists.
+
+if command -v rbenv >/dev/null 2>&1; then
+  LABEL=selenium-ruby
+
+  RBENV_ROOT_DEFAULT="$(rbenv root 2>/dev/null || echo "$HOME/.rbenv")"
+  RUBY_SYMLINK="${RBENV_ROOT_DEFAULT}/versions/${LABEL}"
+  BIN_DIR="${RUBY_SYMLINK}/bin"
+
+  # Always track the directory, even if missing now
+  watch_file "${BIN_DIR}"
+
+  # Only set environment variable if directory currently present
+  if [ -d "${BIN_DIR}" ]; then
+    export RBENV_VERSION="${LABEL}"
+  fi
+fi