Use RESTRICT instead of CASCADE when truncating with postgres

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

spec/support/database_helper.rb

@@ -11,6 +11,7 @@ def self.with_all_dbs &block
   def setup
     Kernel.const_set "User", Class.new(ActiveRecord::Base)
     Kernel.const_set "Agent", Class.new(ActiveRecord::Base)
+    Kernel.const_set "UserProfile", Class.new(ActiveRecord::Base) if db == :postgres
 
     super
 
@@ -25,6 +26,7 @@ def teardown
 
     Kernel.send :remove_const, "User" if defined?(User)
     Kernel.send :remove_const, "Agent" if defined?(Agent)
+    Kernel.send :remove_const, "UserProfile" if defined?(UserProfile)
   end
 
   private
@@ -33,4 +35,25 @@ def establish_connection(config = default_config)
     ActiveRecord::Base.establish_connection(config)
     @connection = ActiveRecord::Base.connection
   end
+
+  def load_schema
+    super
+
+    if db == :postgres
+      connection.execute <<-SQL
+        CREATE TABLE IF NOT EXISTS user_profiles (
+          user_id INTEGER,
+          FOREIGN KEY(user_id) REFERENCES users(id)
+        );
+      SQL
+    end
+  end
+
+  def drop_db
+    if db == :postgres
+      connection.execute "DROP TABLE IF EXISTS user_profiles"
+    end
+
+    super
+  end
 end