1 files changed, 78 insertions, 2 deletions

diff --git a/activerecord/test/cases/calculations_test.rb b/activerecord/test/cases/calculations_test.rb
index d904b802fa..c922a8d1c2 100644
--- a/activerecord/test/cases/calculations_test.rb
+++ b/activerecord/test/cases/calculations_test.rb
@@ -31,11 +31,20 @@ class CalculationsTest < ActiveRecord::TestCase
     assert_equal 318, Account.sum(:credit_limit)
   end
 
+  def test_should_sum_arel_attribute
+    assert_equal 318, Account.sum(Account.arel_table[:credit_limit])
+  end
+
   def test_should_average_field
     value = Account.average(:credit_limit)
     assert_equal 53.0, value
   end
 
+  def test_should_average_arel_attribute
+    value = Account.average(Account.arel_table[:credit_limit])
+    assert_equal 53.0, value
+  end
+
   def test_should_resolve_aliased_attributes
     assert_equal 318, Account.sum(:available_credit)
   end
@@ -60,14 +69,26 @@ class CalculationsTest < ActiveRecord::TestCase
     assert_equal 60, Account.maximum(:credit_limit)
   end
 
+  def test_should_get_maximum_of_arel_attribute
+    assert_equal 60, Account.maximum(Account.arel_table[:credit_limit])
+  end
+
   def test_should_get_maximum_of_field_with_include
     assert_equal 55, Account.where("companies.name != 'Summit'").references(:companies).includes(:firm).maximum(:credit_limit)
   end
 
+  def test_should_get_maximum_of_arel_attribute_with_include
+    assert_equal 55, Account.where("companies.name != 'Summit'").references(:companies).includes(:firm).maximum(Account.arel_table[:credit_limit])
+  end
+
   def test_should_get_minimum_of_field
     assert_equal 50, Account.minimum(:credit_limit)
   end
 
+  def test_should_get_minimum_of_arel_attribute
+    assert_equal 50, Account.minimum(Account.arel_table[:credit_limit])
+  end
+
   def test_should_group_by_field
     c = Account.group(:firm_id).sum(:credit_limit)
     [1,6,2].each do |firm_id|
@@ -102,6 +123,25 @@ class CalculationsTest < ActiveRecord::TestCase
     assert_equal 60,   c[2]
   end
 
+  def test_should_generate_valid_sql_with_joins_and_group
+    assert_nothing_raised ActiveRecord::StatementInvalid do
+      AuditLog.joins(:developer).group(:id).count
+    end
+  end
+
+  def test_should_calculate_against_given_relation
+    developer = Developer.create!(name: "developer")
+    developer.audit_logs.create!(message: "first log")
+    developer.audit_logs.create!(message: "second log")
+
+    c = developer.audit_logs.joins(:developer).group(:id).count
+
+    assert_equal developer.audit_logs.count, c.size
+    developer.audit_logs.each do |log|
+      assert_equal 1, c[log.id]
+    end
+  end
+
   def test_should_order_by_grouped_field
     c = Account.group(:firm_id).order("firm_id").sum(:credit_limit)
     assert_equal [1, 2, 6, 9], c.keys.compact
@@ -131,6 +171,14 @@ class CalculationsTest < ActiveRecord::TestCase
     assert_equal 3, accounts.select(:firm_id).count
   end
 
+  def test_limit_should_apply_before_count_arel_attribute
+    accounts = Account.limit(3).where('firm_id IS NOT NULL')
+
+    firm_id_attribute = Account.arel_table[:firm_id]
+    assert_equal 3, accounts.count(firm_id_attribute)
+    assert_equal 3, accounts.select(firm_id_attribute).count
+  end
+
   def test_count_should_shortcut_with_limit_zero
     accounts = Account.limit(0)
 
@@ -353,10 +401,23 @@ class CalculationsTest < ActiveRecord::TestCase
     assert_equal 6, Account.select("DISTINCT accounts.id").includes(:firm).count
   end
 
+  def test_count_selected_arel_attribute
+    assert_equal 5, Account.select(Account.arel_table[:firm_id]).count
+    assert_equal 4, Account.distinct.select(Account.arel_table[:firm_id]).count
+  end
+
   def test_count_with_column_parameter
     assert_equal 5, Account.count(:firm_id)
   end
 
+  def test_count_with_arel_attribute
+    assert_equal 5, Account.count(Account.arel_table[:firm_id])
+  end
+
+  def test_count_with_arel_star
+    assert_equal 6, Account.count(Arel.star)
+  end
+
   def test_count_with_distinct
     assert_equal 4, Account.select(:credit_limit).distinct.count
 
@@ -378,12 +439,27 @@ class CalculationsTest < ActiveRecord::TestCase
     assert_equal 4, Account.joins(:firm).distinct.count('companies.id')
   end
 
+  def test_count_arel_attribute_in_joined_table_with
+    assert_equal 5, Account.joins(:firm).count(Company.arel_table[:id])
+    assert_equal 4, Account.joins(:firm).distinct.count(Company.arel_table[:id])
+  end
+
+  def test_count_selected_arel_attribute_in_joined_table
+    assert_equal 5, Account.joins(:firm).select(Company.arel_table[:id]).count
+    assert_equal 4, Account.joins(:firm).distinct.select(Company.arel_table[:id]).count
+  end
+
   def test_should_count_field_in_joined_table_with_group_by
     c = Account.group('accounts.firm_id').joins(:firm).count('companies.id')
 
     [1,6,2,9].each { |firm_id| assert c.keys.include?(firm_id) }
   end
 
+  def test_should_count_field_of_root_table_with_conflicting_group_by_column
+    assert_equal({ 1 => 1 }, Firm.joins(:accounts).group(:firm_id).count)
+    assert_equal({ 1 => 1 }, Firm.joins(:accounts).group('accounts.firm_id').count)
+  end
+
   def test_count_with_no_parameters_isnt_deprecated
     assert_not_deprecated { Account.count }
   end
@@ -469,8 +545,8 @@ class CalculationsTest < ActiveRecord::TestCase
     assert_equal 7, Company.includes(:contracts).sum(:developer_id)
   end
 
-  def test_from_option_with_specified_index
-    if Edge.connection.adapter_name == 'MySQL' or Edge.connection.adapter_name == 'Mysql2'
+  if current_adapter?(:Mysql2Adapter)
+    def test_from_option_with_specified_index
       assert_equal Edge.count(:all), Edge.from('edges USE INDEX(unique_edge_index)').count(:all)
       assert_equal Edge.where('sink_id < 5').count(:all),
           Edge.from('edges USE INDEX(unique_edge_index)').where('sink_id < 5').count(:all)