1 files changed, 40 insertions, 1 deletions
diff --git a/spec/ruby/core/kernel/require_spec.rb b/spec/ruby/core/kernel/require_spec.rb
index dc3da4b7e6..19c19e5594 100644
--- a/spec/ruby/core/kernel/require_spec.rb
+++ b/spec/ruby/core/kernel/require_spec.rb
@@ -13,7 +13,46 @@ describe "Kernel#require" do
 
   # if this fails, update your rubygems
   it "is a private method" do
-    Kernel.should have_private_instance_method(:require)
+    Kernel.private_instance_methods(false).should.include?(:require)
+  end
+
+  it "provided features are already required" do
+    provided = %w[complex enumerator fiber rational thread ruby2_keywords]
+    ruby_version_is "4.0" do
+      provided += %w[set pathname]
+    end
+    ruby_version_is "4.1" do
+      provided += %w[monitor]
+    end
+
+    out = ruby_exe("puts $LOADED_FEATURES", options: '--disable-gems --disable-did-you-mean')
+    features = out.lines.map { |line| File.basename(line.chomp, '.*') }
+
+    # Ignore engine-specific internals
+    case RUBY_ENGINE
+    when "jruby"
+      features -= %w[java util]
+    else
+      features -= %w[encdb transdb windows_1252 windows_31]
+    end
+    features.reject! { |feature| feature.end_with?('-fake') }
+
+    features.sort.should == provided.sort
+
+    requires = provided
+    ruby_version_is "4.0" do
+      if RUBY_ENGINE != "jruby"
+        requires = requires.map { |f| f == "pathname" ? "pathname.so" : f }
+      end
+    end
+
+    ruby_version_is "4.1" do
+      requires = requires.map { |f| f == "monitor" ? "monitor.so" : f }
+    end
+
+    code = requires.map { |f| "puts require #{f.inspect}\n" }.join
+    required = ruby_exe(code, options: '--disable-gems')
+    required.should == "false\n" * requires.size
   end
 
   it_behaves_like :kernel_require_basic, :require, CodeLoadingSpecs::Method.new