🐛 Locals with nil value removed before rendering partial #750
Description
nil is a completely valid value of every variable in both Ruby and Ruby on Rails (see RubyGuides) .
nil is a special Ruby object used to represent an “empty” or “default” value
However, turbo-rails removes now all locals that have a nil value. Why does turbo-rails have this inconsistent behaviour?
My code
- Rails version: 8.0.2
- turbo-rails version: 2.16.0
My broadcast_render_to with definition of locals:
# IntakeCase model
broadcast_render_to(
"intake_case:#{id}",
partial: "intake_case/assessment",
locals: {
state: state,
intake_case: self,
question: last_question, # might be nil
replies: las_question&.replies
}
)My partial, rendering an AssessmentComponent with all required arguments:
# _assessment.turbo_stream.erb
<%= turbo_stream.replace "target-tile-center" do %>
<div id="target-tile-center">
<%= render AssessmentComponent.new(
intake_case: intake_case,
question: question,
replies: replies,
) %>
</div>
<% end %>My AssessmentComponent, where I handle the possibility of question being nil or "":
# assessment_component.html.erb
<%if question.blank?%>
<div>
No question
</div>
<%else%>
<div>
Other stuff showing replies
</div>
<%end>Expected behaviour
The local variable last_question is available with value nil and _assessment.turbo_stream.html renders the AssessmentComponent passing question: nil:
# _assessment.turbo_stream.erb
<%= turbo_stream.replace "target-tile-center" do %>
<div id="target-tile-center">
<%= render AssessmentComponent.new(
intake_case: intake_case,
question: nil, # last_question == nil
replies: replies,
) %>
</div>
<% end %>Then component then handles the question being nil or an empty string.
Actual behaviour
undefined local variable or method 'last_question' for an instance of #Class:0x000000032a50f320
The partial _assessment.turbo_stream.html cannot be rendered properly because the local variable last_question is no longer available.