1 files changed, 63 insertions, 0 deletions
diff --git a/app/services/work_items/task_list_reference_removal_service.rb b/app/services/work_items/task_list_reference_removal_service.rb
new file mode 100644
index 00000000000..e7ec73a96e0
--- /dev/null
+++ b/app/services/work_items/task_list_reference_removal_service.rb
@@ -0,0 +1,63 @@
+# frozen_string_literal: true
+
+module WorkItems
+  class TaskListReferenceRemovalService
+    STALE_OBJECT_MESSAGE = 'Stale work item. Check lock version'
+
+    def initialize(work_item:, task:, line_number_start:, line_number_end:, lock_version:, current_user:)
+      @work_item = work_item
+      @task = task
+      @line_number_start = line_number_start
+      @line_number_end = line_number_end
+      @lock_version = lock_version
+      @current_user = current_user
+    end
+
+    def execute
+      return ::ServiceResponse.error(message: 'line_number_start must be greater than 0') if @line_number_start < 1
+      return ::ServiceResponse.error(message: "Work item description can't be blank") if @work_item.description.blank?
+
+      if @line_number_end < @line_number_start
+        return ::ServiceResponse.error(message: 'line_number_end must be greater or equal to line_number_start')
+      end
+
+      source_lines = @work_item.description.split("\n")
+
+      line_matches_reference = (@line_number_start..@line_number_end).any? do |line_number|
+        markdown_line = source_lines[line_number - 1]
+
+        /#{Regexp.escape(@task.to_reference)}(?!\d)/.match?(markdown_line)
+      end
+
+      unless line_matches_reference
+        return ::ServiceResponse.error(
+          message: "Unable to detect a task on lines #{@line_number_start}-#{@line_number_end}"
+        )
+      end
+
+      remove_task_lines!(source_lines)
+
+      ::WorkItems::UpdateService.new(
+        project: @work_item.project,
+        current_user: @current_user,
+        params: { description: source_lines.join("\n"), lock_version: @lock_version }
+      ).execute(@work_item)
+
+      if @work_item.valid?
+        ::ServiceResponse.success
+      else
+        ::ServiceResponse.error(message: @work_item.errors.full_messages)
+      end
+    rescue ActiveRecord::StaleObjectError
+      ::ServiceResponse.error(message: STALE_OBJECT_MESSAGE)
+    end
+
+    private
+
+    def remove_task_lines!(source_lines)
+      source_lines.delete_if.each_with_index do |_line, index|
+        index >= @line_number_start - 1 && index < @line_number_end
+      end
+    end
+  end
+end