Refactor and added specs

2 files changed, 68 insertions, 8 deletions

diff --git a/app/services/issues/update_service.rb b/app/services/issues/update_service.rb
index cf6173da8d4..9c7b8fcc6ab 100644
--- a/app/services/issues/update_service.rb
+++ b/app/services/issues/update_service.rb
@@ -129,17 +129,17 @@ module Issues
       update_task_params = params.delete(:update_task)
       return unless update_task_params
 
-      updated_content = Taskable.toggle_task(issue.description, issue.description_html,
-                                             index: update_task_params[:index],
-                                             currently_checked: !update_task_params[:checked],
-                                             line_source: update_task_params[:line_source],
-                                             line_number: update_task_params[:line_number])
+      toggler = TaskListToggleService.new(issue.description, issue.description_html,
+                                          index: update_task_params[:index],
+                                          currently_checked: !update_task_params[:checked],
+                                          line_source: update_task_params[:line_source],
+                                          line_number: update_task_params[:line_number])
 
-      unless updated_content.empty?
+      if toggler.execute
         # by updating the description_html field at the same time,
         # the markdown cache won't be considered invalid
-        params[:description]      = updated_content[:content]
-        params[:description_html] = updated_content[:content_html]
+        params[:description]      = toggler.updated_markdown
+        params[:description_html] = toggler.updated_markdown_html
 
         # since we're updating a very specific line, we don't care whether
         # the `lock_version` sent from the FE is the same or not.  Just
diff --git a/app/services/task_list_toggle_service.rb b/app/services/task_list_toggle_service.rb
new file mode 100644
index 00000000000..84a875dbaf7
--- /dev/null
+++ b/app/services/task_list_toggle_service.rb
@@ -0,0 +1,60 @@
+# frozen_string_literal: true
+
+# Finds the correct checkbox in the passed in markdown/html and toggles it's state,
+# returning the updated markdown/html
+# We don't care if the text has changed above or below the specific checkbox, as long
+# the checkbox still exists at exactly the same line number and the text is equal
+# If successful, new values are available in `updated_markdown` and `updated_markdown_html`
+class TaskListToggleService
+  attr_reader :updated_markdown, :updated_markdown_html
+
+  def initialize(markdown, markdown_html, index:, currently_checked:, line_source:, line_number:)
+    @markdown, @markdown_html  = markdown, markdown_html
+    @index, @currently_checked = index, currently_checked
+    @line_source, @line_number = line_source, line_number
+
+    @updated_markdown, @updated_markdown_html = nil
+  end
+
+  def execute
+    return false unless markdown && markdown_html
+
+    !!(toggle_markdown && toggle_html)
+  end
+
+  private
+
+  attr_reader :markdown, :markdown_html, :index, :currently_checked, :line_source, :line_number
+
+  def toggle_markdown
+    source_lines  = markdown.split("\n")
+    markdown_task = source_lines[line_number - 1]
+
+    return unless markdown_task == line_source
+    return unless source_checkbox = Taskable::ITEM_PATTERN.match(markdown_task)
+
+    if TaskList::Item.new(source_checkbox[1]).complete?
+      markdown_task.sub!(Taskable::COMPLETE_PATTERN, '[ ]') if currently_checked
+    else
+      markdown_task.sub!(Taskable::INCOMPLETE_PATTERN, '[x]') unless currently_checked
+    end
+
+    source_lines[line_number - 1] = markdown_task
+    @updated_markdown = source_lines.join("\n")
+  end
+
+  def toggle_html
+    html          = Nokogiri::HTML.fragment(markdown_html)
+    html_checkbox = html.css('.task-list-item-checkbox')[index - 1]
+    # html_checkbox = html.css(".task-list-item[data-sourcepos^='#{changed_line_number}:'] > input.task-list-item-checkbox").first
+    return unless html_checkbox
+
+    if currently_checked
+      html_checkbox.remove_attribute('checked')
+    else
+      html_checkbox[:checked] = 'checked'
+    end
+
+    @updated_markdown_html = html.to_html
+  end
+end