init comments

app/models/candidate.rb

@@ -6,6 +6,7 @@ class Candidate < ApplicationRecord
   belongs_to :recruiter, class_name: "User"
   has_many :votes, class_name: "ReviewerVote"
   has_many :reviewers, through: :quiz
+  has_many :quiz_comments, foreign_key: :test_hash, primary_key: :test_hash
 
   serialize :email, CryptSerializer
 

app/models/quiz_comment.rb

@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+class QuizComment < ApplicationRecord
+  belongs_to :user
+  belongs_to :candidate, foreign_key: :test_hash, primary_key: :test_hash
+
+  validates :message, presence: true
+end

app/models/user.rb

@@ -5,6 +5,7 @@ class User < ApplicationRecord
   has_many :reviewer_to_quizzes
   has_many :quizzes, through: :reviewer_to_quizzes
   has_many :votes, class_name: 'ReviewerVote'
+  has_many :quiz_comments
 
   has_many :reviewees, through: :quizzes, source: :candidates