Prefer templates for turbo streams in all but the very simplest cases

(And probably even then)

app/controllers/collections/publications_controller.rb

@@ -3,18 +3,10 @@ class Collections::PublicationsController < ApplicationController
 
   def create
     @collection.publish
-    render turbo_stream: [
-        turbo_stream.replace([ @collection, :publication ], partial: "collections/edit/publication", locals: { collection: @collection }),
-        turbo_stream_flash(notice: "Saved")
-      ]
   end
 
   def destroy
     @collection.unpublish
     @collection.reload
-    render turbo_stream: [
-        turbo_stream.replace([ @collection, :publication ], partial: "collections/edit/publication", locals: { collection: @collection }),
-        turbo_stream_flash(notice: "Saved")
-      ]
   end
 end

app/controllers/concerns/turbo_flash.rb

@@ -1,4 +1,10 @@
 module TurboFlash
+  extend ActiveSupport::Concern
+
+  included do
+    helper_method :turbo_stream_flash
+  end
+
   private
     def turbo_stream_flash(**flash_options)
       turbo_stream.replace(:flash, partial: "layouts/shared/flash", locals: { flash: flash_options })

app/views/collections/publications/create.turbo_stream.erb

@@ -0,0 +1,2 @@
+<%= turbo_stream.replace([ @collection, :publication ], partial: "collections/edit/publication", locals: { collection: @collection }) %>
+<%= turbo_stream_flash(notice: "Saved") %>

app/views/collections/publications/destroy.turbo_stream.erb

@@ -0,0 +1,2 @@
+<%= turbo_stream.replace([ @collection, :publication ], partial: "collections/edit/publication", locals: { collection: @collection }) %>
+<%= turbo_stream_flash(notice: "Saved") %>