helpers for debugging webpacker + rails system test for minitest including printing to the console and disabling uglify

application_system_test_case.rb

# based on https://intellipaat.com/community/16534/is-there-a-way-to-print-javascript-console-errors-to-the-terminal-with-rspec-capybara-selenium

class ApplicationSystemTestCase < ActionDispatch::SystemTestCase
  JavaScriptError = Class.new(StandardError)
  
  driven_by :selenium, using: :headless_chrome, screen_size: [1400, 1400]

  def teardown
    logs = page.driver.browser.manage.logs.get(:browser)
    errors = logs.select { |e| e.level == 'SEVERE' && e.message.present? }

    if errors.present?
      raise JavaScriptError, errors.map(&:message).join("\n\n")
    end
  end
end

config__webpack__test.js

process.env.NODE_ENV = process.env.NODE_ENV || "development";

const environment = require("./environment");
const config = environment.toWebpackConfig();

// turns off uglify per https://github.com/rails/webpacker/issues/1566
delete config.optimization.minimizer;
config.optimization.minimize = false;

module.exports = config;