Publicly indicate if someone edits their comments (#10524)

* Publicly indicate if someone edits their comments

Signed-off-by: Efereyan Karen Simisola <thedevkaren@gmail.com>

* Implement required changes for date edited

* Add methods for readable publish date and edited at in comment decorator

Signed-off-by: Efereyan Karen Simisola <thedevkaren@gmail.com>

* Fix syntax error and decorator naming error

* Add tests

* Update app/views/comments/_comment_date.erb

Co-authored-by: Vaidehi Joshi <vaidehi.sj@gmail.com>

Co-authored-by: rhymes <rhymes@hey.com>
Co-authored-by: Michael Kohl <me@citizen428.net>
Co-authored-by: Vaidehi Joshi <vaidehi.sj@gmail.com>

app/decorators/comment_decorator.rb

@@ -14,4 +14,18 @@ class CommentDecorator < ApplicationDecorator
   def published_at_int
     created_at.to_i
   end
+
+  def edited_timestamp
+    return "" if edited_at.nil?
+
+    edited_at.utc.iso8601
+  end
+
+  def readable_publish_date
+    if created_at.year == Time.current.year
+      created_at.strftime("%b %e")
+    else
+      created_at.strftime("%b %e '%y")
+    end
+  end
 end

app/views/comments/_comment_date.erb

@@ -1,6 +1,15 @@
 <span class="color-base-30 px-2" role="presentation">&bull;</span>
+
 <a href="<%= URL.comment(decorated_comment) %>" class="comment-date crayons-link crayons-link--secondary fs-s">
   <time datetime="<%= decorated_comment.published_timestamp %>">
     <%= decorated_comment.readable_publish_date %>
   </time>
+
+  <% if decorated_comment.edited_at.present? %>
+    &bull; Edited
+    <span class="hidden m:inline-block">
+      on <time datetime="<%= decorated_comment.edited_timestamp %>">
+      <%= decorated_comment.edited_at.strftime('%b %-d') %></time>
+    </span>
+  <% end %>
 </a>

spec/system/comments/user_edits_a_comment_spec.rb

@@ -10,6 +10,7 @@ RSpec.describe "Editing A Comment", type: :system, js: true do
            user: user,
            body_markdown: Faker::Lorem.paragraph)
   end
+  let(:iso8601_datetime_regexp) { /^((\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2})Z)$/ }
 
   before do
     sign_in user
@@ -19,8 +20,16 @@ RSpec.describe "Editing A Comment", type: :system, js: true do
     expect(page).to have_css("textarea")
     expect(page).to have_text("Editing comment")
     fill_in "text-area", with: new_comment_text
+
     click_button("Submit")
+
     expect(page).to have_text(new_comment_text)
+
+    expect(page).to have_text("Edited on")
+    # using .last here because the first `<time>` element is the creation date,
+    # the second one is the time of editing
+    timestamp = page.all(".comment-date time").last[:datetime]
+    expect(timestamp).to match(iso8601_datetime_regexp)
   end
 
   context "when user edits comment on the bottom of the article" do