1 files changed, 40 insertions, 0 deletions
diff --git a/src/arrow/ruby/red-arrow/test/test-rolling-window.rb b/src/arrow/ruby/red-arrow/test/test-rolling-window.rb
new file mode 100644
index 000000000..4158ad162
--- /dev/null
+++ b/src/arrow/ruby/red-arrow/test/test-rolling-window.rb
@@ -0,0 +1,40 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+
+class RollingWindowTest < Test::Unit::TestCase
+  include Helper::Fixture
+
+  def setup
+    raw_table = {
+      :number => Arrow::Int32Array.new([1, -2, nil, 4, 6, 3]),
+    }
+    @table = Arrow::Table.new(raw_table)
+  end
+
+  test("#lag") do
+    assert_equal(<<-ARRAY.chomp, @table.window.lag(:number).to_s)
+[
+  null,
+  -3,
+  null,
+  null,
+  2,
+  -3
+]
+    ARRAY
+  end
+end