Fix Improper Error Handling in Roda

Improper error handling in Roda leads to Information Disclosure. Defaulting to standard Rack backtraces or manual rescue blocks that return 'e.message' exposes your internal file structure, gem versions, and sensitive logic to any script kiddie with a fuzzer. A hardened Roda app must intercept exceptions at the routing level and serve sanitized responses.

The Vulnerable Pattern

class App < Roda
  route do |r|
    r.get 'debug' do
      begin
        # Some logic that fails
        1 / 0
      rescue => e
        # CRITICAL: Leaking internal exception details to the client
        "Error occurred: #{e.message} at #{e.backtrace.first}"
      end
    end
  end
end

The Secure Implementation

The fix utilizes Roda's 'error_handler' plugin, which wraps the routing block in a rescue clause. Instead of letting exceptions bubble up to Rack::ShowExceptions or manually returning 'e.message', we define a global 'error' block. This block logs the raw technical debt to a secure internal stream while returning a sanitized JSON object to the user. This prevents 'stack trace fingerprinting' and ensures attackers gain zero insight into the server-side environment.

class App < Roda
  # Use the error_handler plugin to globally catch exceptions
  plugin :error_handler
  plugin :json
error do |e|
# 1. Log the full trace to a secure sink (stderr/file/Sentry)
$stderr.puts ”[#{Time.now}] #{e.class}: #{e.message}\n#{e.backtrace.join(“\n”)}”
# 2. Scrub the response. Return a generic message and a correlation ID
response.status = 500
{ 
  error: 'Internal Server Error', 
  reference: env['REQUEST_ID'] 
}
end
route do |r|
r.get ‘debug’ do
1 / 0
end
end
end