[rubygems/rubygems] Raise invalid option when bundle open --path is called without a value

https://github.com/rubygems/rubygems/commit/c242311158

lib/bundler/cli.rb

@@ -509,7 +509,7 @@ module Bundler
     subcommand "config", Config
 
     desc "open GEM", "Opens the source directory of the given bundled gem"
-    method_option "path", :type => :string, :banner => "Open relative path of the gem source."
+    method_option "path", :type => :string, :lazy_default => "", :banner => "Open relative path of the gem source."
     def open(name)
       require_relative "cli/open"
       Open.new(options, name).run

lib/bundler/cli/open.rb

@@ -10,6 +10,7 @@ module Bundler
     end
 
     def run
+      raise InvalidOption, "Cannot specify `--path` option without a value" if !@path.nil? && @path.empty?
       editor = [ENV["BUNDLER_EDITOR"], ENV["VISUAL"], ENV["EDITOR"]].find {|e| !e.nil? && !e.empty? }
       return Bundler.ui.info("To open a bundled gem, set $EDITOR or $BUNDLER_EDITOR") unless editor
       return unless spec = Bundler::CLI::Common.select_spec(name, :regex_match)

spec/bundler/commands/open_spec.rb

@@ -73,6 +73,11 @@ RSpec.describe "bundle open" do
       expect(out).to include("editor #{default_bundle_path("gems", "activerecord-2.3.2")}/lib/active_record")
     end
 
+    it "requires value for --path arg" do
+      bundle "open activerecord --path", :env => { "EDITOR" => "echo editor", "VISUAL" => "", "BUNDLER_EDITOR" => "" }, :raise_on_error => false
+      expect(err).to eq "Cannot specify `--path` option without a value"
+    end
+
     it "suggests alternatives for similar-sounding gems when using subpath" do
       bundle "open Rails --path README.md", :env => { "EDITOR" => "echo editor", "VISUAL" => "", "BUNDLER_EDITOR" => "" }, :raise_on_error => false
       expect(err).to match(/did you mean rails\?/i)