DEV: Update username in new quote format - Part 1 (#22032)

When we introduced the new quote format with full-name display name:

```
[quote="Ted Johansson, post:1, topic:2, username:ted"]
we overlooked the code responsible for rewriting quotes when a user's name is changed.
```

The functional part of this change adds support for the new quote format in the code that updates quotes when a user's username changes. See the test case in `spec/services/username_changer_spec.rb` for the details.

In addition, this change adds a regression test for PrettyText to cover the new quote format, and extracts the code responsible for rewriting raw and cooked quotes into its own `QuoteRewriter` class. The functionality of the latter is tested through the tests in `spec/services/username_changer_spec.rb`.

app/jobs/regular/update_username.rb

@@ -11,7 +11,10 @@ module Jobs
 
       @old_username = args[:old_username].unicode_normalize
       @new_username = args[:new_username].unicode_normalize
-      @avatar_img = PrettyText.avatar_img(args[:avatar_template], "tiny")
+
+      avatar_img = PrettyText.avatar_img(args[:avatar_template], "tiny")
+
+      @quote_rewriter = QuoteRewriter.new(@user_id, @old_username, @new_username, avatar_img)
 
       @raw_mention_regex =
         /
@@ -26,13 +29,10 @@ module Jobs
         )
       /ix
 
-      @raw_quote_regex = /(\[quote\s*=\s*["'']?)#{@old_username}(\,?[^\]]*\])/i
-
       cooked_username = PrettyText::Helpers.format_username(@old_username)
       @cooked_mention_username_regex = /\A@#{cooked_username}\z/i
       @cooked_mention_user_path_regex =
         %r{\A/u(?:sers)?/#{UrlHelper.encode_component(cooked_username)}\z}i
-      @cooked_quote_username_regex = /(?<=\s)#{cooked_username}(?=:)/i
 
       update_posts
       update_revisions
@@ -160,10 +160,7 @@ module Jobs
     end
 
     def update_raw(raw)
-      raw.gsub(@raw_mention_regex, "@#{@new_username}").gsub(
-        @raw_quote_regex,
-        "\\1#{@new_username}\\2",
-      )
+      @quote_rewriter.rewrite_raw(raw.gsub(@raw_mention_regex, "@#{@new_username}"))
     end
 
     # Uses Nokogiri instead of rebake, because it works for posts and revisions
@@ -182,28 +179,7 @@ module Jobs
           ) if a["href"]
         end
 
-      doc
-        .css("aside.quote")
-        .each do |aside|
-          next unless div = aside.at_css("div.title")
-
-          username_replaced = false
-
-          aside["data-username"] = @new_username if aside["data-username"] == @old_username
-
-          div.children.each do |child|
-            if child.text?
-              content = child.content
-              username_replaced =
-                content.gsub!(@cooked_quote_username_regex, @new_username).present?
-              child.content = content if username_replaced
-            end
-          end
-
-          if username_replaced || quotes_correct_user?(aside)
-            div.at_css("img.avatar")&.replace(@avatar_img)
-          end
-        end
+      @quote_rewriter.rewrite_cooked(doc)
 
       doc.to_html
     end

lib/quote_rewriter.rb

@@ -0,0 +1,54 @@
+# frozen_string_literal: true
+
+class QuoteRewriter
+  def initialize(user_id, old_username, new_username, avatar_img)
+    @user_id = user_id
+    @old_username = old_username
+    @new_username = new_username
+    @avatar_img = avatar_img
+  end
+
+  def rewrite_raw(raw)
+    pattern =
+      Regexp.union(
+        /(?<pre>\[quote\s*=\s*["'']?.*username:)#{old_username}(?<post>\,?[^\]]*\])/i,
+        /(?<pre>\[quote\s*=\s*["'']?)#{old_username}(?<post>\,?[^\]]*\])/i,
+      )
+
+    raw.gsub(pattern, "\\k<pre>#{new_username}\\k<post>")
+  end
+
+  def rewrite_cooked(cooked)
+    pattern = /(?<=\s)#{PrettyText::Helpers.format_username(old_username)}(?=:)/i
+
+    cooked
+      .css("aside.quote")
+      .each do |aside|
+        next unless div = aside.at_css("div.title")
+
+        username_replaced = false
+
+        aside["data-username"] = new_username if aside["data-username"] == old_username
+
+        div.children.each do |child|
+          if child.text?
+            content = child.content
+            username_replaced = content.gsub!(pattern, new_username).present?
+            child.content = content if username_replaced
+          end
+        end
+
+        if username_replaced || quotes_correct_user?(aside)
+          div.at_css("img.avatar")&.replace(avatar_img)
+        end
+      end
+  end
+
+  private
+
+  attr_reader :user_id, :old_username, :new_username, :avatar_img
+
+  def quotes_correct_user?(aside)
+    Post.exists?(topic_id: aside["data-topic"], post_number: aside["data-post"], user_id: user_id)
+  end
+end

spec/lib/pretty_text_spec.rb

@@ -28,6 +28,28 @@ RSpec.describe PrettyText do
 
       before { User.stubs(:default_template).returns(default_avatar) }
 
+      it "correctly extracts usernames from the new quote format" do
+        topic = Fabricate(:topic, title: "this is a test topic :slight_smile:")
+        expected = <<~HTML
+          <aside class="quote no-group" data-username="codinghorror" data-post="2" data-topic="#{topic.id}">
+          <div class="title">
+          <div class="quote-controls"></div>
+          <a href="http://test.localhost/t/this-is-a-test-topic/#{topic.id}/2">This is a test topic <img width="20" height="20" src="/images/emoji/twitter/slight_smile.png?v=#{Emoji::EMOJI_VERSION}" title="slight_smile" loading="lazy" alt="slight_smile" class="emoji"></a>
+          </div>
+          <blockquote>
+          <p>ddd</p>
+          </blockquote>
+          </aside>
+        HTML
+
+        expect(
+          cook(
+            "[quote=\"Jeff, post:2, topic:#{topic.id}, username:codinghorror\"]\nddd\n[/quote]",
+            topic_id: 1,
+          ),
+        ).to eq(n(expected))
+      end
+
       it "do off topic quoting with emoji unescape" do
         topic = Fabricate(:topic, title: "this is a test topic :slight_smile:")
         expected = <<~HTML

spec/services/username_changer_spec.rb

@@ -494,6 +494,41 @@ RSpec.describe UsernameChanger do
           HTML
         end
 
+        it "replaces the username in new quote format" do
+          post = create_post_and_change_username(raw: <<~RAW)
+            Lorem ipsum
+
+            [quote="Foo Bar, post:1, topic:#{quoted_post.topic.id}, username:foo"]
+            quoted post
+            [/quote]
+
+            dolor sit amet
+          RAW
+
+          expect(post.raw).to eq(<<~RAW.strip)
+            Lorem ipsum
+
+            [quote="Foo Bar, post:1, topic:#{quoted_post.topic.id}, username:bar"]
+            quoted post
+            [/quote]
+
+            dolor sit amet
+          RAW
+
+          expect(post.cooked).to match_html(<<~HTML)
+            <p>Lorem ipsum</p>
+            <aside class="quote no-group" data-username="bar" data-post="1" data-topic="#{quoted_post.topic.id}">
+            <div class="title">
+            <div class="quote-controls"></div>
+            <img loading="lazy" alt="" width="24" height="24" src="//test.localhost/letter_avatar_proxy/v4/letter/b/b77776/48.png" class="avatar"> Foo Bar:</div>
+            <blockquote>
+            <p>quoted post</p>
+            </blockquote>
+            </aside>
+            <p>dolor sit amet</p>
+          HTML
+        end
+
         context "when there is a simple quote" do
           let(:raw) { <<~RAW }
               Lorem ipsum
@@ -599,7 +634,6 @@ RSpec.describe UsernameChanger do
                 quoted post
               </blockquote>
             </aside>
-
             <aside class="quote" data-post="#{another_quoted_post.post_number}" data-topic="#{another_quoted_post.topic.id}">
               <div class="title">
                 <div class="quote-controls"></div>