Rails 6 upgrades to rails notes command and introduction of Rails::Command::NotesCommand

rails notes is used to search your code in a Rails application to find comments beginning with specific keywords.

Rails 6 adds Rails::Command::NotesCommand to follow the pattern for Rails::Commands. It also introduces some useful changes to the rails notes API.

The old rake notes usage has been modified to call that newer command under the hood with a deprecation warning when called with the old API.

Before Rails 6

Previously, one had to use environment variable to find comments beginning with custom keywords.

For instance, to find comments starting with frozen_string_literal,

$ rails notes:custom ANNOTATION=frozen_string_literal
app/channels/application_cable/channel.rb:
  * [1] true

app/channels/application_cable/connection.rb:
  * [1] true

Also, we could use certain tags directly. For instance, to find comments starting with TODO,

$ rails notes:todo
app/models/user.rb:
  * [14] Send email after registration

Rails 6

With Rails 6, we can seamlessly use --annotations argument to either search for default tags or pass specific annotation(s).

For instance, to find comments beginning with default tags (FIXME, OPTIMIZE, TODO),

$ rails notes --annotations
app/controllers/admin/users_controller.rb:
  * [ 40] [TODO] move business logic to model
  * [144] [FIXME] needs urgent attention for next deployment

lib/school.rb:
  * [ 18] [OPTIMIZE] refactor to a faster sql query

And to find annotations with custom tags,

$ rails notes --annotations REFACTOR FIXME
app/controllers/products_controller.rb:
  * [ 55] [REFACTOR] need to refactor this controller code

app/controllers/admin/users_controller.rb:
  * [144] [FIXME] needs urgent attention for next deployment

Note that the old rails notes:custom, rails notes:fixme, rails notes:todo, rails notes:optimize have been marked as deprecated.

Calling any notes command with rake instead of rails has also been deprecated.