FIX: Ensure Rack::Test::UploadedFile closes its tempfile file descriptor on GC

.gitignore

@@ -6,3 +6,4 @@ VERSION
 *.rbc
 *.swp
 /.bundle
+/.idea

lib/rack/test/uploaded_file.rb

@@ -30,6 +30,8 @@ def initialize(path, content_type = "text/plain", binary = false)
         @tempfile.set_encoding(Encoding::BINARY) if @tempfile.respond_to?(:set_encoding)
         @tempfile.binmode if binary
 
+        ObjectSpace.define_finalizer(self, self.class.finalize(@tempfile))
+
         FileUtils.copy_file(path, @tempfile.path)
       end
 
@@ -47,6 +49,15 @@ def respond_to?(method_name, include_private = false) #:nodoc:
         @tempfile.respond_to?(method_name, include_private) || super
       end
 
+      def self.finalize(file)
+        proc { actually_finalize file }
+      end
+
+      def self.actually_finalize(file)
+        file.close
+        file.unlink
+      end
+
     end
 
   end

spec/rack/test/uploaded_file_spec.rb

@@ -5,6 +5,12 @@ def test_file_path
     File.dirname(__FILE__) + "/../../fixtures/foo.txt"
   end
 
+  it "returns an instance of `Rack::Test::UploadedFile`" do
+    uploaded_file = Rack::Test::UploadedFile.new(test_file_path)
+
+    expect(uploaded_file).to be_a(Rack::Test::UploadedFile)
+  end
+
   it "responds to things that Tempfile responds to" do
     uploaded_file = Rack::Test::UploadedFile.new(test_file_path)
 
@@ -26,4 +32,29 @@ def test_file_path
 
     expect(File.extname(uploaded_file.path)).to eq(".txt")
   end
+
+  context "it should call its destructor" do
+    it "calls the destructor" do
+      expect(Rack::Test::UploadedFile).to receive(:actually_finalize).at_least(:once)
+
+      if RUBY_PLATFORM == 'java' && RUBY_VERSION == '2.3.1'
+        require 'java'
+        java_import 'java.lang.System'
+
+        20.times do |i|
+          uploaded_file = Rack::Test::UploadedFile.new(test_file_path)
+
+          uploaded_file = nil
+
+          System.gc()
+        end
+      else
+        uploaded_file = Rack::Test::UploadedFile.new(test_file_path)
+
+        uploaded_file = nil
+
+        GC.start
+      end
+    end
+  end
 end