1 files changed, 69 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..981ec2e34b
--- /dev/null
+++ b/activerecord/test/cases/arel/nodes/over_test.rb
@@ -0,0 +1,69 @@
+# 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