1 files changed, 20 insertions, 1 deletions
diff --git a/test/ruby/test_lazy_enumerator.rb b/test/ruby/test_lazy_enumerator.rb
index 4dddbab50c..3652096237 100644
--- a/test/ruby/test_lazy_enumerator.rb
+++ b/test/ruby/test_lazy_enumerator.rb
@@ -608,7 +608,7 @@ EOS
   end
 
   def test_require_block
-    %i[select reject drop_while take_while map flat_map].each do |method|
+    %i[select reject drop_while take_while map flat_map tap_each].each do |method|
       assert_raise(ArgumentError){ [].lazy.send(method) }
     end
   end
@@ -715,4 +715,23 @@ EOS
   def test_with_index_size
     assert_equal(3, Enumerator::Lazy.new([1, 2, 3], 3){|y, v| y << v}.with_index.size)
   end
+
+  def test_tap_each
+    out = []
+
+    e = (1..Float::INFINITY).lazy
+                            .tap_each { |x| out << x }
+                            .select(&:even?)
+                            .first(5)
+
+    assert_equal([1, 2, 3, 4, 5, 6, 7, 8, 9, 10], out)
+    assert_equal([2, 4, 6, 8, 10], e)
+  end
+
+  def test_tap_each_is_not_intrusive
+    s = Step.new(1..3)
+
+    assert_equal(2, s.lazy.tap_each { |x| x }.map { |x| x * 2 }.first)
+    assert_equal(1, s.current)
+  end
 end