4 files changed, 47 insertions, 1 deletions
diff --git a/test/ostruct/test_ostruct.rb b/test/ostruct/test_ostruct.rb
index dca2382b2b..1826e40e53 100644
--- a/test/ostruct/test_ostruct.rb
+++ b/test/ostruct/test_ostruct.rb
@@ -73,4 +73,16 @@ class TC_OpenStruct < Test::Unit::TestCase
     assert_raise(NoMethodError) { o[:foo] }
   end
 
+  def test_to_h
+    h = {name: "John Smith", age: 70, pension: 300}
+    os = OpenStruct.new(h)
+    to_h = os.to_h
+    assert_equal(h, to_h)
+
+    to_h[:age] = 71
+    assert_equal(70, os.age)
+    assert_equal(70, h[:age])
+
+    assert_equal(h, OpenStruct.new("name" => "John Smith", "age" => 70, pension: 300).to_h)
+  end
 end
diff --git a/test/ruby/test_env.rb b/test/ruby/test_env.rb
index 9166f4df6c..8baf762472 100644
--- a/test/ruby/test_env.rb
+++ b/test/ruby/test_env.rb
@@ -327,6 +327,10 @@ class TestEnv < Test::Unit::TestCase
     assert_equal(h, ENV.to_hash)
   end
 
+  def test_to_h
+    assert_equal(ENV.to_hash, ENV.to_h)
+  end
+
   def test_reject
     h1 = {}
     ENV.each_pair {|k, v| h1[k] = v }
diff --git a/test/ruby/test_hash.rb b/test/ruby/test_hash.rb
index e3c92125c5..0c03bf4726 100644
--- a/test/ruby/test_hash.rb
+++ b/test/ruby/test_hash.rb
@@ -77,7 +77,7 @@ class TestHash < Test::Unit::TestCase
   # From rubicon
 
   def setup
-    @cls = Hash
+    @cls ||= Hash
     @h = @cls[
       1 => 'one', 2 => 'two', 3 => 'three',
       self => 'self', true => 'true', nil => 'nil',
@@ -631,6 +631,20 @@ class TestHash < Test::Unit::TestCase
   def test_to_hash
     h = @h.to_hash
     assert_equal(@h, h)
+    assert_instance_of(@cls, h)
+  end
+
+  def test_to_h
+    h = @h.to_h
+    assert_equal(@h, h)
+    assert_instance_of(Hash, h)
+  end
+
+  def test_nil_to_h
+    h = nil.to_h
+    assert_equal({}, h)
+    assert_nil(h.default)
+    assert_nil(h.default_proc)
   end
 
   def test_to_s
@@ -932,4 +946,14 @@ class TestHash < Test::Unit::TestCase
       assert_not_equal(h.hash, h.invert.hash, feature4262)
     end
   end
+
+  class TestSubHash < TestHash
+    class SubHash < Hash
+    end
+
+    def setup
+      @cls = SubHash
+      super
+    end
+  end
 end
diff --git a/test/ruby/test_struct.rb b/test/ruby/test_struct.rb
index d769e47dc5..b3191902a3 100644
--- a/test/ruby/test_struct.rb
+++ b/test/ruby/test_struct.rb
@@ -263,4 +263,10 @@ class TestStruct < Test::Unit::TestCase
     end
     assert_equal("Insecure: can't modify #{st}::S", error.message, bug5036)
   end
+
+  def test_to_h
+    klass = Struct.new(:a, :b, :c, :d, :e, :f)
+    o = klass.new(1, 2, 3, 4, 5, 6)
+    assert_equal({a:1, b:2, c:3, d:4, e:5, f:6}, o.to_h)
+  end
 end