How to test CRUD operations in Rails

A lot of the functionality in web applications boil down to CRUD operations (Create, Read, Update, Delete). If you can get good test coverage for these operations, you’re in a good place. Let’s consider how you can use feature tests to test that users can successfuly CRUD a Quote resource.

How to organize feature tests

Here’s a possible folder structure:

├── spec
│   ├── features
│   │   ├── quotes
|   |   |   └── quotes_index_spec.rb
|   |   |   └── create_quote_spec.rb
|   |   |   └── show_quote_spec.rb
|   |   |   └── update_quote_spec.rb
|   |   |   └── delete_quote_spec.rb

Let’s consider what each spec might look like:

Index spec

• Index page requires authentication (not always a requirement).
• Index page shows empty items message when there are no items.
• Index page only lists items belonging to user (not always a requirement).
• Index page shows correct number of items per page (not always a requirement).

Create spec

• Create page requires user to be authenticated.
• When form submission is invalid, validation errors are shown.
• When form submission is valid, resource is created.
  • Success message is shown.
  • User is redirected to some route (usually index route of resource).
  • Resource is created in the database with the new attributes.

Show spec

• Only the resource’s owner can view the quote details (not always a requirement).
• User can view the show page.

Update spec

• Edit page requires user to be authenticated.
• Only the resource’s owner can view the edit page.
• Only the resource’s owner can update the resource (see this post for testing strategy approach).
• When form submission is invalid, validation errors are shown.
• When form submission is valid, resource is updated with new values.
  • Success message is shown.
  • User is redirected to some route (usually index route of resource).
  • Resource is updated in the database with the new attributes.

Delete spec

• Only the resource’s owner can delete the resource.
• User can delete the resource.
  • Success message is shown.
  • User is redirected to some route (usually index route of resource).
  • Resource is deleted from the database.