Use RESTRICT instead of CASCADE when truncating with postgres

Author: Bartosz Suchodolski

lib/database_cleaner/active_record/truncation.rb

@@ -189,7 +189,7 @@ def database_tables
 
         def truncate_tables(table_names)
           return if table_names.nil? || table_names.empty?
-          execute("TRUNCATE TABLE #{table_names.map{|name| quote_table_name(name)}.join(', ')} RESTART IDENTITY CASCADE;")
+          execute("TRUNCATE TABLE #{table_names.map{|name| quote_table_name(name)}.join(', ')} RESTART IDENTITY RESTRICT;")
         end
 
         def pre_count_truncate_tables(tables)

spec/database_cleaner/active_record/truncation_spec.rb

@@ -33,6 +33,7 @@
           before do
             2.times { User.create! }
             2.times { Agent.create! }
+            UserProfile.create!(user_id: User.first.id) if helper.db == :postgres
           end
 
           it "should truncate all tables" do
@@ -42,6 +43,13 @@
               .to([0,0])
           end
 
+          if helper.db == :postgres
+            it "should raise exception when trying to truncate table referenced in a foreign key constraint" do
+              expect { described_class.new(except: ['user_profiles']).clean }
+                .to raise_error(ActiveRecord::StatementInvalid, /cannot truncate a table referenced in a foreign key constraint/)
+            end
+          end
+
           it "should reset AUTO_INCREMENT index of table" do
             strategy.clean
             expect(User.create.id).to eq 1