誤り

def test_method
  Rails.logger.info('one')
  Rails.logger.info('two') #<= raise
end

logger_mock = Minitest::Mock.new
info_mock = logger_mock.expect(:info, true, ['one'])
Rails.logger = logger_mock

test_method <= No more expects available for :info

正解

logger_mock = Minitest::Mock.new
info_mock = logger_mock.expect(:info, true, ['one']).expect(:info, true, ['two'])
Rails.logger = logger_mock

ruby - Minitest: No more expects available - Stack Overflow