diff --git a/test/test_helper.rb b/test/test_helper.rb
index f1da754..3495ef3 100644
--- a/test/test_helper.rb
+++ b/test/test_helper.rb
@@ -87,8 +87,8 @@ class ActiveSupport::TestCase
   alias :ok :assert_block
 
   def assert_equivalent(enum1, enum2)
-    norm1 = enum1.to_a
-    norm2 = enum2.to_a
+    norm1 = enum1.group_by{|e|e}.values
+    norm2 = enum2.group_by{|e|e}.values
     assert_equal norm1.size, norm2.size, "Size mismatch: #{enum1.inspect} vs #{enum2.inspect}"
     assert_equal [], norm1 - norm2
     assert_equal [], norm2 - norm1
diff --git a/test/unit/helper_test.rb b/test/unit/helper_test.rb
new file mode 100644
index 0000000..f09475c
--- /dev/null
+++ b/test/unit/helper_test.rb
@@ -0,0 +1,62 @@
+require_relative "../test_helper"
+
+class HelperTest < ActiveSupport::TestCase
+
+  should 'assert_equivalent be true for the same arrays' do
+    a1 = [1,2,3]
+    a2 = [1,2,3]
+    assert_equivalent a1, a2
+  end
+
+  should 'assert_equivalent be true for equivalent arrays' do
+    a1 = [1,2,3]
+    a2 = [3,2,1]
+    assert_equivalent a1, a2
+  end
+
+  should 'assert_equivalent be true for equivalent arrays independent of parameter order' do
+    a1 = [1,2,3]
+    a2 = [3,2,1]
+    assert_equivalent a2, a1
+  end
+
+  should 'assert_equivalent be false for different arrays' do
+    a1 = [1,2,3]
+    a2 = [4,2,1]
+    assert_raise Minitest::Assertion do
+      assert_equivalent(a1, a2)
+    end
+  end
+
+  should 'assert_equivalent be false for different arrays independent of parameter order' do
+    a1 = [1,2,3]
+    a2 = [4,2,1]
+    assert_raise Minitest::Assertion do
+      assert_equivalent(a2, a1)
+    end
+  end
+
+  should 'assert_equivalent be false for arrays with different sizes' do
+    a1 = [1,2,3]
+    a2 = [1,2,3,4]
+    assert_raise Minitest::Assertion do
+      assert_equivalent(a1, a2)
+    end
+  end
+
+  should 'assert_equivalent be false for arrays with same elements duplicated' do
+    a1 = [2,2,3]
+    a2 = [2,3,3]
+    assert_raise Minitest::Assertion do
+      assert_equivalent(a1, a2)
+    end
+  end
+
+  should 'assert_equivalent be false for arrays with same elements duplicated of different sizes' do
+    a1 = [2,2,3]
+    a2 = [2,3,3,3]
+    assert_raise Minitest::Assertion do
+      assert_equivalent(a1, a2)
+    end
+  end
+end
--
libgit2 0.21.2