1 files changed, 42 insertions, 0 deletions
diff --git a/activerecord/test/cases/arel/nodes/extract_test.rb b/activerecord/test/cases/arel/nodes/extract_test.rb
new file mode 100644
index 0000000000..f6dc1626a4
--- /dev/null
+++ b/activerecord/test/cases/arel/nodes/extract_test.rb
@@ -0,0 +1,42 @@
+# frozen_string_literal: true
+require_relative '../helper'
+
+class Arel::Nodes::ExtractTest < Arel::Spec
+  it "should extract field" do
+    table = Arel::Table.new :users
+    table[:timestamp].extract('date').to_sql.must_be_like %{
+      EXTRACT(DATE FROM "users"."timestamp")
+    }
+  end
+
+  describe "as" do
+    it 'should alias the extract' do
+      table = Arel::Table.new :users
+      table[:timestamp].extract('date').as('foo').to_sql.must_be_like %{
+        EXTRACT(DATE FROM "users"."timestamp") AS foo
+      }
+    end
+
+    it 'should not mutate the extract' do
+      table = Arel::Table.new :users
+      extract = table[:timestamp].extract('date')
+      before = extract.dup
+      extract.as('foo')
+      assert_equal extract, before
+    end
+  end
+
+  describe 'equality' do
+    it 'is equal with equal ivars' do
+      table = Arel::Table.new :users
+      array = [table[:attr].extract('foo'), table[:attr].extract('foo')]
+      assert_equal 1, array.uniq.size
+    end
+
+    it 'is not equal with different ivars' do
+      table = Arel::Table.new :users
+      array = [table[:attr].extract('foo'), table[:attr].extract('bar')]
+      assert_equal 2, array.uniq.size
+    end
+  end
+end