Module: HttpMimic::SpaDetector

Defined in:
lib/http_mimic/spa_detector.rb

Constant Summary collapse

EMPTY_MOUNT_REGEX =

Framework mount points that indicate an unhydrated SPA client shell

%r{
  <div[^>]+id=["'](?:root|app|__next|__nuxt|svelte)["'][^>]*>\s*</div>|
  <app-root[^>]*>\s*</app-root>|
  <div[^>]+id=["']app["'][^>]*>\s*<!--\s*(?:app-content)?\s*-->\s*</div>
}ix
NOSCRIPT_JS_REQUIRED_REGEX =

Noscript patterns requiring JavaScript execution

%r{
  <noscript[^>]*>[\s\S]*?(?:enable\s+javascript|javascript\s+is\s+required|need\s+to\s+enable\s+javascript|requires\s+javascript)[\s\S]*?</noscript>
}ix
GOOGLE_SHELL_REGEX =

Google Search Guard dynamic SPA shell indicators

%r{
  (?:/httpservice/retry/enablejs|SG_REL|emsg=SG_REL|knitsail)
}ix

Class Method Summary collapse

Class Method Details

.empty_mount_point?(body) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/http_mimic/spa_detector.rb', line 60

def empty_mount_point?(body)
  body.match?(EMPTY_MOUNT_REGEX)
end

.google_serp_shell?(body) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/http_mimic/spa_detector.rb', line 68

def google_serp_shell?(body)
  return false unless body.match?(GOOGLE_SHELL_REGEX)

  # If it has the Google shell indicators AND lacks rendered organic result elements
  !body.include?('<h3 class=') && !body.include?('id="search"') && !body.include?('id="rso"')
end

.low_text_js_heavy_shell?(body) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/http_mimic/spa_detector.rb', line 75

def low_text_js_heavy_shell?(body)
  return false if body.length > 25_000 # Larger HTML files typically have SSR content

  # Check if there are script tags
  script_count = body.scan(/<script/i).size
  return false if script_count.zero?

  # Strip all HTML tags, scripts, and styles to get raw visible text length
  visible_text = body
                 .gsub(/<script[\s\S]*?<\/script>/i, '')
                 .gsub(/<style[\s\S]*?<\/style>/i, '')
                 .gsub(/<[^>]+>/, ' ')
                 .gsub(/\s+/, ' ')
                 .strip

  # If visible text is virtually nonexistent but page has multiple scripts
  visible_text.length < 80 && script_count >= 2
end

.noscript_js_required?(body) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/http_mimic/spa_detector.rb', line 64

def noscript_js_required?(body)
  body.match?(NOSCRIPT_JS_REQUIRED_REGEX)
end

.spa?(response) ⇒ Boolean

Returns true if the HTTP response represents an unhydrated Single Page Application (SPA) shell

Parameters:

Returns:

  • (Boolean) 


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# File 'lib/http_mimic/spa_detector.rb', line 27

def spa?(response)
  return false unless response && response.success?
  return false if response.respond_to?(:binary?) && response.binary?

  content_type = response.headers['content-type'].to_s.downcase
  return false unless content_type.empty? || content_type.include?('text/html') || content_type.include?('application/xhtml')

  body = response.body.to_s
  return false if body.strip.empty?

  # 1. Google Dynamic SERP / Search Guard JS Shell
  if google_serp_shell?(body)
    return true
  end

  # 2. Modern SPA framework empty mount points (React, Vue, Angular, Next, Nuxt, Svelte)
  if empty_mount_point?(body)
    return true
  end

  # 3. Noscript requirement message
  if noscript_js_required?(body)
    return true
  end

  # 4. Small body with multiple scripts and virtually no visible text
  if low_text_js_heavy_shell?(body)
    return true
  end

  false
end