3 files changed, 61 insertions, 9 deletions
diff --git a/activerecord/test/cases/finder_test.rb b/activerecord/test/cases/finder_test.rb
index 75a74c052d..cbeb37dd22 100644
--- a/activerecord/test/cases/finder_test.rb
+++ b/activerecord/test/cases/finder_test.rb
@@ -506,7 +506,7 @@ class FinderTest < ActiveRecord::TestCase
     end
   end
 
-  def test_take_and_first_and_last_with_integer_should_use_sql_limit
+  def test_take_and_first_and_last_with_integer_should_use_sql
     assert_sql(/LIMIT|ROWNUM <=/) { Topic.take(3).entries }
     assert_sql(/LIMIT|ROWNUM <=/) { Topic.first(2).entries }
     assert_sql(/LIMIT|ROWNUM <=/) { Topic.last(5).entries }
@@ -516,16 +516,30 @@ class FinderTest < ActiveRecord::TestCase
     assert_equal Topic.order("title").to_a.last(2), Topic.order("title").last(2)
   end
 
-  def test_last_with_integer_and_order_should_not_use_sql_limit
-    query = assert_sql { Topic.order("title").last(5).entries }
-    assert_equal 1, query.length
-    assert_no_match(/LIMIT/, query.first)
+  def test_last_with_integer_and_order_should_use_sql
+    relation = Topic.order("title")
+    assert_queries(1) { relation.last(5) }
+    assert !relation.loaded?
   end
 
-  def test_last_with_integer_and_reorder_should_not_use_sql_limit
-    query = assert_sql { Topic.reorder("title").last(5).entries }
-    assert_equal 1, query.length
-    assert_no_match(/LIMIT/, query.first)
+  def test_last_with_integer_and_reorder_should_use_sql
+    relation = Topic.reorder("title")
+    assert_queries(1) { relation.last(5) }
+    assert !relation.loaded?
+  end
+
+  def test_last_on_loaded_relation_should_not_use_sql
+    relation  = Topic.limit(10).load
+    assert_no_queries do
+      relation.last
+      relation.last(2)
+    end
+  end
+
+  def test_last_with_irreversible_order
+    assert_deprecated do
+      Topic.order("coalesce(author_name, title)").last
+    end
   end
 
   def test_take_and_first_and_last_with_integer_should_return_an_array
diff --git a/activerecord/test/cases/inheritance_test.rb b/activerecord/test/cases/inheritance_test.rb
index c870247a4a..7da6842047 100644
--- a/activerecord/test/cases/inheritance_test.rb
+++ b/activerecord/test/cases/inheritance_test.rb
@@ -493,6 +493,10 @@ class InheritanceComputeTypeTest < ActiveRecord::TestCase
     assert_equal 'Firm', firm.type
     assert_instance_of Firm, firm
 
+    client = Client.new
+    assert_equal 'Client', client.type
+    assert_instance_of Client, client
+
     firm = Company.new(type: 'Client') # overwrite the default type
     assert_equal 'Client', firm.type
     assert_instance_of Client, firm
diff --git a/activerecord/test/cases/relations_test.rb b/activerecord/test/cases/relations_test.rb
index 0638edacbd..090b885dd5 100644
--- a/activerecord/test/cases/relations_test.rb
+++ b/activerecord/test/cases/relations_test.rb
@@ -19,6 +19,7 @@ require 'models/aircraft'
 require "models/possession"
 require "models/reader"
 require "models/categorization"
+require "models/edge"
 
 class RelationTest < ActiveRecord::TestCase
   fixtures :authors, :topics, :entrants, :developers, :companies, :developers_projects, :accounts, :categories, :categorizations, :posts, :comments,
@@ -223,6 +224,39 @@ class RelationTest < ActiveRecord::TestCase
     assert_equal topics(:fifth).title, topics.first.title
   end
 
+  def test_reverse_order_with_function
+    topics = Topic.order("length(title)").reverse_order
+    assert_equal topics(:second).title, topics.first.title
+  end
+
+  def test_reverse_order_with_function_other_predicates
+    topics = Topic.order("author_name, length(title), id").reverse_order
+    assert_equal topics(:second).title, topics.first.title
+    topics = Topic.order("length(author_name), id, length(title)").reverse_order
+    assert_equal topics(:fifth).title, topics.first.title
+  end
+
+  def test_reverse_order_with_multiargument_function
+    assert_raises(ActiveRecord::IrreversibleOrderError) do
+      Topic.order("concat(author_name, title)").reverse_order
+    end
+  end
+
+  def test_reverse_order_with_nulls_first_or_last
+    assert_raises(ActiveRecord::IrreversibleOrderError) do
+      Topic.order("title NULLS FIRST").reverse_order
+    end
+    assert_raises(ActiveRecord::IrreversibleOrderError) do
+      Topic.order("title nulls last").reverse_order
+    end
+  end
+
+  def test_default_reverse_order_on_table_without_primary_key
+    assert_raises(ActiveRecord::IrreversibleOrderError) do
+      Edge.all.reverse_order
+    end
+  end
+
   def test_order_with_hash_and_symbol_generates_the_same_sql
     assert_equal Topic.order(:id).to_sql, Topic.order(:id => :asc).to_sql
   end