2 files changed, 104 insertions, 0 deletions
diff --git a/activerecord/test/cases/relation/or_test.rb b/activerecord/test/cases/relation/or_test.rb
new file mode 100644
index 0000000000..2006fc9611
--- /dev/null
+++ b/activerecord/test/cases/relation/or_test.rb
@@ -0,0 +1,84 @@
+require "cases/helper"
+require 'models/post'
+
+module ActiveRecord
+  class OrTest < ActiveRecord::TestCase
+    fixtures :posts
+
+    def test_or_with_relation
+      expected = Post.where('id = 1 or id = 2').to_a
+      assert_equal expected, Post.where('id = 1').or(Post.where('id = 2')).to_a
+    end
+
+    def test_or_identity
+      expected = Post.where('id = 1').to_a
+      assert_equal expected, Post.where('id = 1').or(Post.where('id = 1')).to_a
+    end
+
+    def test_or_with_null_left
+      expected = Post.where('id = 1').to_a
+      assert_equal expected, Post.none.or(Post.where('id = 1')).to_a
+    end
+
+    def test_or_with_null_right
+      expected = Post.where('id = 1').to_a
+      assert_equal expected, Post.where('id = 1').or(Post.none).to_a
+    end
+
+    def test_or_with_bind_params
+      assert_equal Post.find([1, 2]), Post.where(id: 1).or(Post.where(id: 2)).to_a
+    end
+
+    def test_or_with_null_both
+      expected = Post.none.to_a
+      assert_equal expected, Post.none.or(Post.none).to_a
+    end
+
+    def test_or_without_left_where
+      expected = Post.all
+      assert_equal expected, Post.or(Post.where('id = 1')).to_a
+    end
+
+    def test_or_without_right_where
+      expected = Post.all
+      assert_equal expected, Post.where('id = 1').or(Post.all).to_a
+    end
+
+    def test_or_preserves_other_querying_methods
+      expected = Post.where('id = 1 or id = 2 or id = 3').order('body asc').to_a
+      partial = Post.order('body asc')
+      assert_equal expected, partial.where('id = 1').or(partial.where(:id => [2, 3])).to_a
+      assert_equal expected, Post.order('body asc').where('id = 1').or(Post.order('body asc').where(:id => [2, 3])).to_a
+    end
+
+    def test_or_with_incompatible_relations
+      assert_raises ArgumentError do
+        Post.order('body asc').where('id = 1').or(Post.order('id desc').where(:id => [2, 3])).to_a
+      end
+    end
+
+    def test_or_when_grouping
+      groups = Post.where('id < 10').group('body').select('body, COUNT(*) AS c')
+      expected = groups.having("COUNT(*) > 1 OR body like 'Such%'").to_a.map {|o| [o.body, o.c] }
+      assert_equal expected, groups.having('COUNT(*) > 1').or(groups.having("body like 'Such%'")).to_a.map {|o| [o.body, o.c] }
+    end
+
+    def test_or_with_named_scope
+      expected = Post.where("id = 1 or body LIKE '\%a\%'").to_a
+      assert_equal expected, Post.where('id = 1').or(Post.containing_the_letter_a)
+    end
+
+    def test_or_inside_named_scope
+      expected = Post.where("body LIKE '\%a\%' OR title LIKE ?", "%'%").order('id DESC').to_a
+      assert_equal expected, Post.order(id: :desc).typographically_interesting
+    end
+
+    def test_or_on_loaded_relation
+      expected = Post.where('id = 1 or id = 2').to_a
+      p = Post.where('id = 1')
+      p.load
+      assert_equal p.loaded?, true
+      assert_equal expected, p.or(Post.where('id = 2')).to_a
+    end
+  end
+end
diff --git a/activerecord/test/cases/relation/where_clause_test.rb b/activerecord/test/cases/relation/where_clause_test.rb
index db18980e0b..c20ed94d90 100644
--- a/activerecord/test/cases/relation/where_clause_test.rb
+++ b/activerecord/test/cases/relation/where_clause_test.rb
@@ -145,6 +145,26 @@ class ActiveRecord::Relation
       assert_equal where_clause.ast, where_clause_with_empty.ast
     end
 
+    test "or joins the two clauses using OR" do
+      where_clause = WhereClause.new([table["id"].eq(bind_param)], [attribute("id", 1)])
+      other_clause = WhereClause.new([table["name"].eq(bind_param)], [attribute("name", "Sean")])
+      expected_ast =
+        Arel::Nodes::Grouping.new(
+          Arel::Nodes::Or.new(table["id"].eq(bind_param), table["name"].eq(bind_param))
+        )
+      expected_binds = where_clause.binds + other_clause.binds
+
+      assert_equal expected_ast.to_sql, where_clause.or(other_clause).ast.to_sql
+      assert_equal expected_binds, where_clause.or(other_clause).binds
+    end
+
+    test "or returns an empty where clause when either side is empty" do
+      where_clause = WhereClause.new([table["id"].eq(bind_param)], [attribute("id", 1)])
+
+      assert_equal WhereClause.empty, where_clause.or(WhereClause.empty)
+      assert_equal WhereClause.empty, WhereClause.empty.or(where_clause)
+    end
+
     private
 
     def table