[rubygems/rubygems] Simplify spec wording and implementation

https://github.com/rubygems/rubygems/commit/3e7f1379fb

spec/bundler/install/gemfile/force_ruby_platform_spec.rb

@@ -115,46 +115,31 @@ RSpec.describe "bundle install with force_ruby_platform DSL option", :jruby do
       expect(the_bundle).to include_gems "platform_specific 1.0.0 #{Bundler.local_platform}"
     end
 
-    it "uses ruby variants for the explicit transitive dependency with a lockile that has only ruby platform" do
+    it "reinstalls the ruby variant when a platform specific variant is already installed, the lockile has only RUBY platform, and :force_ruby_platform is used in the Gemfile" do
       lockfile <<-L
         GEM
           remote: #{file_uri_for(gem_repo4)}
           specs:
-            dep_level_2 (1.0)
-              depends_on_platform_specific
-            depends_on_platform_specific (1.0)
-              platform_specific
             platform_specific (1.0)
 
         PLATFORMS
           ruby
 
         DEPENDENCIES
-          dep_level_2
           platform_specific
 
         BUNDLED WITH
             #{Bundler::VERSION}
       L
 
-      install_gemfile <<-G, :env => { "BUNDLER_SPEC_GEM_REPO" => gem_repo4.to_s }, :artifice => "compact_index", :verbose => true
+      system_gems "platform_specific-1.0-#{Gem::Platform.local}", :path => default_bundle_path
-        source "#{file_uri_for(gem_repo4)}"
-
-        gem "platform_specific"
-        gem "depends_on_platform_specific"
-      G
-
-      expect(the_bundle).to include_gems "depends_on_platform_specific 1.0.0 #{Bundler.local_platform}"
-      expect(the_bundle).to include_gems "platform_specific 1.0.0 #{Bundler.local_platform}"
 
       install_gemfile <<-G, :env => { "BUNDLER_SPEC_GEM_REPO" => gem_repo4.to_s }, :artifice => "compact_index"
         source "#{file_uri_for(gem_repo4)}"
 
         gem "platform_specific", :force_ruby_platform => true
-        gem "depends_on_platform_specific"
       G
 
-      expect(the_bundle).to include_gems "depends_on_platform_specific 1.0.0 #{Bundler.local_platform}"
       expect(the_bundle).to include_gems "platform_specific 1.0.0 RUBY"
     end
   end