Class: ReactOnRails::TestHelper::DevAssetsDetector

Inherits:
Object
  • Object
show all
Defined in:
lib/react_on_rails/test_helper/dev_assets_detector.rb

Overview

Detects whether development webpack assets can be reused for tests, avoiding redundant compilation when ‘bin/dev static` is already running.

When ‘bin/dev static` runs webpack in watch mode, it writes compiled assets to the development output directory (e.g., public/packs). If those assets are fresh (newer than all source files) and not HMR artifacts, tests can reuse them instead of running a separate build_test_command.

This makes ‘bundle exec rspec` “just work” when `bin/dev static` is running, with no environment variables or extra commands needed.

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.try_activate_dev_assets! ⇒ Object

Attempts to detect and activate development assets for test use.

When successful:

  • Overrides Shakapacker’s test config to point at dev output

  • Clears manifest cache so tests read the dev manifest

  • Returns true

When dev assets aren’t usable (HMR mode, stale, missing):

  • Returns false with no side effects



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# File 'lib/react_on_rails/test_helper/dev_assets_detector.rb', line 31

def try_activate_dev_assets!
  reset_hmr_warning_state!
  detector = new
  result = detector.check
  return false unless result

  return false unless apply_shakapacker_override!(result)

  print_activation_message(result)
  true
rescue StandardError => e
  warn "React on Rails: Dev asset detection failed: #{e.message}" if ENV["DEBUG"]
  false
end

Instance Method Details

#check ⇒ Object

Checks if development assets are reusable for tests.

Returns a hash with dev output info if reusable, nil otherwise.



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# File 'lib/react_on_rails/test_helper/dev_assets_detector.rb', line 100

def check
  shakapacker_yml = load_shakapacker_yml
  return nil unless shakapacker_yml

  dev_output = resolve_dev_output(shakapacker_yml)
  return nil unless dev_output

  manifest_path = dev_output[:dev_full_path].join("manifest.json")
  return nil unless manifest_usable?(manifest_path)

  dev_output.merge(manifest_path: manifest_path)
end