[deploy] Remove redirect on comments#update (#10337)

* Remove redirect on comments#update

* Delete unecessary view

* Refactor to account for orgs and podcasts

* Code cleanup

* Add specs

* Fix podcast comment update

* Add more safe navigation operators

* Update safe nav operators again

* Update comment to explain more

app/controllers/comments_controller.rb

@@ -141,7 +141,33 @@ class CommentsController < ApplicationController
     authorize @comment
     if @comment.update(permitted_attributes(@comment).merge(edited_at: Time.zone.now))
       Mention.create_all(@comment)
-      redirect_to URI.parse(@comment.path).path, notice: "Comment was successfully updated."
+
+      # The following sets variables used in the index view. We render the
+      # index view directly to avoid having to redirect.
+      #
+      # Redirects lead to a race condition where we redirect to a cached view
+      # after updating data and we don't bust the cache fast enough before
+      # hitting the view, therefore stale content ends up being served from
+      # cache.
+      #
+      # https://github.com/forem/forem/issues/10338#issuecomment-693401481
+      @on_comments_page = true
+      @root_comment = @comment
+      @commentable = @comment.commentable
+      @commentable_type = @comment.commentable_type
+
+      case @commentable_type
+      when "PodcastEpisode"
+        @user = @commentable&.podcast
+      when "Article"
+        # user could be a user or an organization
+        @user = @commentable&.user
+        @article = @commentable
+      else
+        @user = @commentable&.user
+      end
+
+      render :index
     else
       @commentable = @comment.commentable
       render :edit

spec/requests/comments_update_spec.rb

@@ -17,4 +17,13 @@ RSpec.describe "CommentsUpdate", type: :request do
     }
     expect(Comment.last.processed_html).to include(new_body)
   end
+
+  it "doesn't redirect" do
+    new_body = "NEW TITLE #{rand(100)}"
+    put "/comments/#{comment.id}", params: {
+      comment: { body_markdown: new_body }
+    }
+    expect(response).not_to have_http_status(:redirect)
+    expect(response).to have_http_status(:ok)
+  end
 end