1 files changed, 20 insertions, 2 deletions
diff --git a/mrbgems/mruby-enum-ext/test/enum.rb b/mrbgems/mruby-enum-ext/test/enum.rb
index 9523b497e..ba0851582 100644
--- a/mrbgems/mruby-enum-ext/test/enum.rb
+++ b/mrbgems/mruby-enum-ext/test/enum.rb
@@ -47,11 +47,21 @@ assert("Enumerable#sort_by") do
 end
 
 assert("Enumerable#first") do
-  a = [1, 2, 3]
+  a = Object.new
+  a.extend Enumerable
+  def a.each
+    yield 1
+    yield 2
+    yield 3
+  end
   assert_equal 1, a.first
   assert_equal [1, 2], a.first(2)
   assert_equal [1, 2, 3], a.first(10)
-  assert_nil [].first
+  a = Object.new
+  a.extend Enumerable
+  def a.each
+  end
+  assert_nil a.first
 end
 
 assert("Enumerable#count") do
@@ -66,3 +76,11 @@ assert("Enumerable#flat_map") do
   assert_equal [1, -1, 2, -2, 3, -3, 4, -4], [1, 2, 3, 4].flat_map { |e| [e, -e] }
   assert_equal [1, 2, 100, 3, 4, 100], [[1, 2], [3, 4]].flat_map { |e| e + [100] }
 end
+
+assert("Enumerable#max_by") do
+  assert_equal "albatross", %w[albatross dog horse].max_by { |x| x.length }
+end
+
+assert("Enumerable#min_by") do
+  assert_equal "dog", %w[albatross dog horse].min_by { |x| x.length }
+end