## Code Review: Ticket #123 - Comment Parent ID Fix ✓ PASS ### Bug 500 error when adding comments - `undefined method 'parent_id' for Comment` ### Root Cause The `_comment.html.haml` partial uses: - Line 3: `comment.parent_id` for styling nested comments (`ml-8 border-gray-200` vs `border-gray-300`) - Line 43: `comment.children` for rendering nested replies - Line 36: `parent_id` hidden field in reply form But the Comment model lacked the `parent_id` column and parent/child associations. ### Fix Applied #### 1. Migration (`add_parent_id_to_comments.rb`) ```ruby add_column :comments, :parent_id, :bigint add_index :comments, :parent_id add_foreign_key :comments, :comments, column: :parent_id ``` #### 2. Model Associations ```ruby belongs_to :parent, class_name: "Comment", optional: true has_many :children, class_name: "Comment", foreign_key: :parent_id, dependent: :destroy ``` #### 3. Bonus Fix `broadcast_comment` now passes `ticket: ticket` local to partial (was missing, would cause errors when broadcasting new comments). ### Acceptance Criteria Met - ✓ Comments can be added without 500 error (parent_id column exists) - ✓ Comment partial renders correctly (associations implemented) - ✓ Threading properly implemented with optional parent ### Code Quality - Optional parent allows top-level comments (no orphaned root comments) - `dependent: :destroy` on children prevents orphaned replies - Foreign key constraint ensures referential integrity - Index on parent_id for query performance - Tests cover parent/child relationships ### No Issues Found Clean bug fix with proper database schema, associations, and test coverage. Ready to merge.