Heroku CI with rails fixtures

heroku, heroku-ci, ruby-on-rails

Solution

Rails PR which fixed this issue was reverted: https://github.com/rails/rails/pull/27636

Workaround is monkey patch:

# config/initializers/disable_referential_integrity.rb
require "activerecord/lib/active_record/connection_adapters/postgresql/referential_integrity.rb"
require "activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb"

Add to your `lib/` two files (code from rails PR):

# lib/activerecord/lib/active_record/connection_adapters/postgresql/referential_integrity.rb
module ActiveRecord
  module ConnectionAdapters
    module PostgreSQL
      module ReferentialIntegrity # :nodoc:
        def supports_disable_referential_integrity? # :nodoc:
          true
        end

        def disable_referential_integrity(&block) # :nodoc:
          if supports_disable_referential_integrity?
            if supports_alter_constraint?
              disable_referential_integrity_with_alter_constraint(&block)
            else
              disable_referential_integrity_with_disable_trigger(&block)
            end
          else
            yield
          end
        end

        private

          def disable_referential_integrity_with_alter_constraint
            tables_constraints = execute(<<-SQL).values
              SELECT table_name, constraint_name
              FROM information_schema.table_constraints
              WHERE constraint_type = 'FOREIGN KEY'
              AND is_deferrable = 'NO'
            SQL

            execute(
              tables_constraints.collect { |table, constraint|
                "ALTER TABLE #{quote_table_name(table)} ALTER CONSTRAINT #{constraint} DEFERRABLE"
              }.join(";")
            )

            begin
              transaction do
                execute("SET CONSTRAINTS ALL DEFERRED")

                yield
              end
            ensure
              execute(
                tables_constraints.collect { |table, constraint|
                  "ALTER TABLE #{quote_table_name(table)} ALTER CONSTRAINT #{constraint} NOT DEFERRABLE"
                }.join(";")
              )
            end
          end

          def disable_referential_integrity_with_disable_trigger
            original_exception = nil

            begin
              transaction(requires_new: true) do
                execute(tables.collect { |name| "ALTER TABLE #{quote_table_name(name)} DISABLE TRIGGER ALL" }.join(";"))
              end
            rescue ActiveRecord::ActiveRecordError => e
              original_exception = e
            end

            begin
              yield
            rescue ActiveRecord::InvalidForeignKey => e
              warn <<-WARNING
WARNING: Rails was not able to disable referential integrity.
This is most likely caused due to missing permissions.
Rails needs superuser privileges to disable referential integrity.
    cause: #{original_exception.try(:message)}
              WARNING
              raise e
            end

            begin
              transaction(requires_new: true) do
                execute(tables.collect { |name| "ALTER TABLE #{quote_table_name(name)} ENABLE TRIGGER ALL" }.join(";"))
              end
            rescue ActiveRecord::ActiveRecordError
            end
          end
      end
    end
  end
end

and second file:

# lib/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
module ActiveRecord
  module ConnectionAdapters
    class PostgreSQLAdapter < AbstractAdapter

      def supports_alter_constraint?
        # PostgreSQL 9.4 introduces ALTER TABLE ... ALTER CONSTRAINT but it has a bug and fixed in 9.4.2
        # https://www.postgresql.org/docs/9.4/static/release-9-4-2.html
        postgresql_version >= 90402
      end

    end
  end
end

Problem

Original source