1 files changed, 33 insertions, 0 deletions
diff --git a/test/ruby/test_file.rb b/test/ruby/test_file.rb
index aa10566bfa..9fa96f8a7c 100644
--- a/test/ruby/test_file.rb
+++ b/test/ruby/test_file.rb
@@ -460,6 +460,39 @@ class TestFile < Test::Unit::TestCase
     end
   end
 
+  def test_initialize
+    Dir.mktmpdir(__method__.to_s) do |tmpdir|
+      path = File.join(tmpdir, "foo")
+
+      assert_raise(Errno::ENOENT) {File.new(path)}
+      f = File.new(path, "w")
+      f.write("FOO\n")
+      f.close
+      f = File.new(path)
+      data = f.read
+      f.close
+      assert_equal("FOO\n", data)
+
+      f = File.new(path, File::WRONLY)
+      f.write("BAR\n")
+      f.close
+      f = File.new(path, File::RDONLY)
+      data = f.read
+      f.close
+      assert_equal("BAR\n", data)
+
+      data = File.open(path) {|file|
+        File.new(file.fileno, mode: File::RDONLY, autoclose: false).read
+      }
+      assert_equal("BAR\n", data)
+
+      data = File.open(path) {|file|
+        File.new(file.fileno, File::RDONLY, autoclose: false).read
+      }
+      assert_equal("BAR\n", data)
+    end
+  end
+
   def test_file_open_newline_option
     Dir.mktmpdir(__method__.to_s) do |tmpdir|
       path = File.join(tmpdir, "foo")