[rubygems/rubygems] Extract logic to manipulate RUBYLIB in specs to a helper

https://github.com/rubygems/rubygems/commit/0057382bb1

spec/bundler/bundler/shared_helpers_spec.rb

@@ -258,8 +258,7 @@ RSpec.describe Bundler::SharedHelpers do
 
       it "ensures bundler's ruby version lib path is in ENV['RUBYLIB']" do
         subject.set_bundle_environment
-        paths = (ENV["RUBYLIB"]).split(File::PATH_SEPARATOR)
-        expect(paths).to include(ruby_lib_path)
+        expect(rubylib).to include(ruby_lib_path)
       end
     end
 
@@ -276,8 +275,7 @@ RSpec.describe Bundler::SharedHelpers do
 
       subject.set_bundle_environment
 
-      paths = (ENV["RUBYLIB"]).split(File::PATH_SEPARATOR)
-      expect(paths.count(RbConfig::CONFIG["rubylibdir"])).to eq(0)
+      expect(rubylib.count(RbConfig::CONFIG["rubylibdir"])).to eq(0)
     end
 
     it "exits if bundle path contains the unix-like path separator" do
@@ -441,8 +439,7 @@ RSpec.describe Bundler::SharedHelpers do
 
       it "ENV['RUBYLIB'] should only contain one instance of bundler's ruby version lib path" do
         subject.set_bundle_environment
-        paths = (ENV["RUBYLIB"]).split(File::PATH_SEPARATOR)
-        expect(paths.count(ruby_lib_path)).to eq(1)
+        expect(rubylib.count(ruby_lib_path)).to eq(1)
       end
     end
   end

spec/bundler/commands/install_spec.rb

@@ -238,8 +238,7 @@ RSpec.describe "bundle install with gem sources" do
     it "loads env plugins" do
       plugin_msg = "hello from an env plugin!"
       create_file "plugins/rubygems_plugin.rb", "puts '#{plugin_msg}'"
-      rubylib = ENV["RUBYLIB"].to_s.split(File::PATH_SEPARATOR).unshift(bundled_app("plugins").to_s).join(File::PATH_SEPARATOR)
-      install_gemfile <<-G, env: { "RUBYLIB" => rubylib }
+      install_gemfile <<-G, env: { "RUBYLIB" => rubylib.unshift(bundled_app("plugins").to_s).join(File::PATH_SEPARATOR) }
         source "https://gem.repo1"
         gem "myrack"
       G

spec/bundler/support/env.rb

@@ -5,5 +5,9 @@ module Spec
     def ruby_core?
       File.exist?(File.expand_path("../../../lib/bundler/bundler.gemspec", __dir__))
     end
+
+    def rubylib
+      ENV["RUBYLIB"].to_s.split(File::PATH_SEPARATOR)
+    end
   end
 end