1 files changed, 68 insertions, 0 deletions
diff --git a/activerecord/test/cases/arel/nodes/over_test.rb b/activerecord/test/cases/arel/nodes/over_test.rb
new file mode 100644
index 0000000000..c9804c395f
--- /dev/null
+++ b/activerecord/test/cases/arel/nodes/over_test.rb
@@ -0,0 +1,68 @@
+# frozen_string_literal: true
+require_relative '../helper'
+
+class Arel::Nodes::OverTest < Arel::Spec
+  describe 'as' do
+    it 'should alias the expression' do
+      table = Arel::Table.new :users
+      table[:id].count.over.as('foo').to_sql.must_be_like %{
+        COUNT("users"."id") OVER () AS foo
+      }
+    end
+  end
+
+  describe 'with literal' do
+    it 'should reference the window definition by name' do
+      table = Arel::Table.new :users
+      table[:id].count.over('foo').to_sql.must_be_like %{
+        COUNT("users"."id") OVER "foo"
+      }
+    end
+  end
+
+  describe 'with SQL literal' do
+    it 'should reference the window definition by name' do
+      table = Arel::Table.new :users
+      table[:id].count.over(Arel.sql('foo')).to_sql.must_be_like %{
+        COUNT("users"."id") OVER foo
+      }
+    end
+  end
+
+  describe 'with no expression' do
+    it 'should use empty definition' do
+      table = Arel::Table.new :users
+      table[:id].count.over.to_sql.must_be_like %{
+        COUNT("users"."id") OVER ()
+      }
+    end
+  end
+
+  describe 'with expression' do
+    it 'should use definition in sub-expression' do
+      table = Arel::Table.new :users
+      window = Arel::Nodes::Window.new.order(table['foo'])
+      table[:id].count.over(window).to_sql.must_be_like %{
+        COUNT("users"."id") OVER (ORDER BY \"users\".\"foo\")
+      }
+    end
+  end
+
+  describe 'equality' do
+    it 'is equal with equal ivars' do
+      array = [
+        Arel::Nodes::Over.new('foo', 'bar'),
+        Arel::Nodes::Over.new('foo', 'bar')
+      ]
+      assert_equal 1, array.uniq.size
+    end
+
+    it 'is not equal with different ivars' do
+      array = [
+        Arel::Nodes::Over.new('foo', 'bar'),
+        Arel::Nodes::Over.new('foo', 'baz')
+      ]
+      assert_equal 2, array.uniq.size
+    end
+  end
+end