add mutations to questions and reviews

app/graphql/mutations/create_question.rb

@@ -0,0 +1,35 @@
+# frozen_string_literal: true
+
+module Mutations
+  class CreateQuestion < BaseMutation
+    field :question, Types::QuestionType, null: true
+
+    argument :question, Inputs::QuestionCreateInput, required: true
+
+    def resolve(question:)
+      question = question.to_h
+      reviewer_user_id = question.delete(:reviewer_user_id)
+
+      record = Question.new(question)
+      record.user_id = context[:current_user].id
+
+      policy = QuestionPolicy.new(context[:current_user], record)
+
+      raise Pundit::NotAuthorizedError unless policy.create?
+
+      ActiveRecord::Base.transaction do
+        record.save!
+
+        if reviewer_user_id.present? && question[:status] != "draft"
+          record.review_requests.create!(user_id: reviewer_user_id)
+        end
+
+        { question: record, errors: [] }
+      rescue ActiveRecord::RecordInvalid
+        { question: nil, errors: record.errors.full_messages }
+      end
+    rescue Pundit::NotAuthorizedError => e
+      { question: nil, errors: [e.message] }
+    end
+  end
+end