Rails controller method to show an optionally scaled image using MiniMagick

Question

I've got below implementation for my controller and show action which implements MiniMagick gem. I've just wondering is there any better way to write it down? If block in a separate, private method maybe?

 def show
 identification_document = IdentificationDocument.find(params[:id])
 authorize identification_document
 return unless identification_document
 if params.has_key?(:thumbnail)
 document = identification_document.id_document
 image = MiniMagick::Image.read(document.file.read)
 image.resize("50x60")
 scaled_image_bytes = image.to_blob
 send_data(scaled_image_bytes, filename: identification_document.file_name)
 else 
 send_data(identification_document.id_document.file.read, filename: identification_document.file_name)
 end
 end

Answer 1

Rubocop Report

Conventions

Prefer key? over has_key? (PreferredHashMethods).

if params.has_key?(:thumbnail)

if params.key?(:thumbnail)

---

Prefer single quoted over double quoted string literals if you don't need interpolation or special symbols (StringLiterals).

image.resize("50x60")

image.resize('50x60')

---

Complexity

If block in a separate, private method maybe?

The AbcSize complexity of your method is too high. [19.65/15] So your suggestion to put the following code in a private method, is justified.

 document = identification_document.id_document
 image = MiniMagick::Image.read(document.file.read)
 image.resize("50x60")
 scaled_image_bytes = image.to_blob

---

Readability

Keep line sizes below 80 characters:

send_data(identification_document.id_document.file.read, filename: identification_document.file_name)

• ekampp: The under 80 chars rule is outdated. Screens have gotten significantly bigger and more pixels are available. There should definitely be a max char length enforced, but it can easily be 120 or 150 depending on the developers setups in an organization.
• ekampp: Single quote vs double quote is against the rails convention. Rails convention is double quotes all around, so I would suggest keeping the double quotes.
• dfhwze: @ekampp Thanks for the feedback, you have a link to more recent guidelines, or are you talking out of personal experience?
• ekampp: regarding the 80 char rule, that's from experience. The Rails convention if from reading the Rails documentation and source code.