1 files changed, 38 insertions, 0 deletions
diff --git a/spec/ruby/core/enumerator/new_spec.rb b/spec/ruby/core/enumerator/new_spec.rb
index 170809dbc1..15e42d247e 100644
--- a/spec/ruby/core/enumerator/new_spec.rb
+++ b/spec/ruby/core/enumerator/new_spec.rb
@@ -38,4 +38,42 @@ describe "Enumerator.new" do
     end
     enum.to_a.should == [:bar]
   end
+
+  context "when passed a block" do
+    it "defines iteration with block, yielder argument and calling << method" do
+      enum = Enumerator.new do |yielder|
+        a = 1
+
+        loop do
+          yielder << a
+          a = a + 1
+        end
+      end
+
+      enum.take(3).should == [1, 2, 3]
+    end
+
+    it "defines iteration with block, yielder argument and calling yield method" do
+      enum = Enumerator.new do |yielder|
+        a = 1
+
+        loop do
+          yielder.yield(a)
+          a = a + 1
+        end
+      end
+
+      enum.take(3).should == [1, 2, 3]
+    end
+
+    ruby_version_is "2.7" do
+      it "defines iteration with block, yielder argument and treating it as a proc" do
+        enum = Enumerator.new do |yielder|
+          "a\nb\nc".each_line(&yielder)
+        end
+
+        enum.to_a.should == ["a\n", "b\n", "c"]
+      end
+    end
+  end
 end