Public and assets folders in Ruby on Rails - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Purpose of the public folder in Rails

What is the main role of the public folder in a Rails application?

A It contains Ruby source code files for models and controllers.

B It holds compiled assets like JavaScript and CSS after precompilation.

C It stores static files that are served directly by the web server without Rails processing.

D It is used to store database migration files.

💡 Hint

Think about files that the server can send without running Ruby code.

The public folder holds static files like images, robots.txt, or favicon.ico that the web server can serve directly without involving Rails code.

❓ component_behavior

intermediate

Behavior of assets in the assets folder

Which statement best describes how files in the app/assets folder are handled in a Rails app?

A They contain only Ruby code for asset management.

B They are served directly by the web server without any processing.

C They are ignored by Rails and must be manually copied to the public folder.

D They are compiled and served through the asset pipeline, allowing preprocessing and fingerprinting.

💡 Hint

Consider how Rails prepares CSS and JavaScript files before sending them to the browser.

Files in app/assets are processed by the asset pipeline. This allows Rails to preprocess, compress, and fingerprint them for caching.

📝 Syntax

advanced

Correct asset reference in Rails views

Which option correctly references an image named logo.png stored in app/assets/images inside a Rails ERB view?

Ruby on Rails

<%= ??? %>

A <%= asset_path('logo.png') %>

B <%= image_tag 'logo.png' %>

C <%= image_path('logo.png') %>

D <%= image_url('logo.png') %>

💡 Hint

Think about the helper that generates an HTML tag.

image_tag generates an HTML element with the correct path to the asset. The others return just the URL or path string.

🔧 Debug

advanced

Why is a new image not showing in production?

You added new_image.png to app/assets/images but it does not appear in production after deployment. What is the most likely cause?

A The asset pipeline was not recompiled, so the new image is missing in the precompiled assets.

B The image file is in the wrong folder; it should be in public/images.

C Rails does not support PNG images in assets.

D The image tag helper is deprecated and does not work.

💡 Hint

Think about what happens to assets when deploying to production.

In production, Rails serves precompiled assets. If you add a new asset, you must recompile assets so the new file is included.

❓ state_output

expert

Result of accessing a file in public vs assets folder

Given a file named example.txt placed in both public and app/assets folders, what happens when a browser requests /example.txt in production?

A The file from the public folder is served directly; the asset pipeline ignores the request.

B The asset pipeline serves the file from app/assets with fingerprinting applied.

C Rails returns a 404 error because the file exists in two places.

D The file from app/assets is served without fingerprinting.

💡 Hint

Remember how the web server handles files in public vs assets folders.

Files in the public folder are served directly by the web server. Requests to /example.txt will return the public file, ignoring app/assets.