Route definition in routes.rb in Ruby on Rails - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ component_behavior

intermediate

What is the output of this route helper?

Given the following route definition in routes.rb, what URL will posts_path generate?

Rails.application.routes.draw do
  resources :posts, only: [:index, :show]
end

A "/posts"

B "/posts/index"

C "/posts/show"

D "/post"

💡 Hint

The posts_path helper corresponds to the index action URL for posts.

The resources :posts creates RESTful routes. The posts_path helper generates the URL for the index action, which is /posts.

📝 Syntax

intermediate

Which route definition correctly creates a nested resource?

You want to define routes so that comments belong to posts, accessible via URLs like /posts/:post_id/comments. Which option correctly defines this in routes.rb?

A

resource :posts do
  resource :comments
end

B

resources :posts do
  resources :comments
end

C

resources :comments do
  resources :posts
end

D resources :posts, :comments

💡 Hint

Nested resources are defined by placing one resources block inside another.

Option B correctly nests comments inside posts, creating URLs like /posts/:post_id/comments.

🔧 Debug

advanced

Why does this route cause a routing error?

Given this route definition:

get 'profile/:id', to: 'users#show'

And this URL request: /profile
What error will Rails raise?

A ArgumentError

B ActionController::UrlGenerationError

C NoMethodError

D ActionController::RoutingError

💡 Hint

The URL is missing a required parameter defined in the route.

The route expects an :id parameter, but the URL /profile does not provide it. This causes a routing error because no matching route is found.

❓ state_output

advanced

What is the HTTP verb and path for this custom route?

Consider this route in routes.rb:

post 'subscribe', to: 'newsletters#subscribe'

What HTTP verb and path does this route respond to?

A POST /subscribe

B DELETE /subscribe

C PUT /subscribe

D GET /subscribe

💡 Hint

The first word in the route definition is the HTTP verb.

The route responds to HTTP POST requests at the path /subscribe.

🧠 Conceptual

expert

How many routes are created by this line?

What is the total number of routes generated by this line in routes.rb?

resources :articles, only: [:index, :show, :create, :update, :destroy]

A 3

B 7

C 5

D 6

💡 Hint

Each action in the only list creates one route.

The only option limits routes to the specified actions. Each action corresponds to one route, so 5 actions create 5 routes.