```ruby
require "rails_helper"

describe CommentsController do
  describe 'GET #index' do
    it 'populates an array of all comment to a question' do
      comment1 = create(:q_comment)
      comment2 = create(:q_comment)
      get :index, :commentable_id => 1, :commentable_type => "Question", format: :json
      expect(assigns(:q_comment)).to match_array([comment1, comment2])
    end
    it 'populates an array of all comment to an answer' do
      comment1 = create(:a_comment)
      comment2 = create(:a_comment)
      get :index, commentable_id: 1, commentable_type: "Answer"
      expect(assigns(:q_question)).to match_array([comment1, comment2])
    end

  end

  describe 'GET #show' do

  end

  describe 'GET #new' do

  end

  describe 'GET #edit' do
  end

  describe 'POST #create' do

  end
end```

Define initial rspec tests for comments controller.
user
```ruby
require "rails_helper"

describe CommentsController do
  describe 'POST #create' do
    it 'adds a comment to the comments table'
    it 'does not save a comment without a body'
  end

  describe 'GET #edit' do
    it 'renders an edit form with original body text'
  end

  describe 'PUT #update' do
    it 'updates the comment in the comments table'
    it 'does not update a comment without a body'
  end

  describe 'DELETE #destroy' do
    it 'deletes the comment from the comments table'
    it 're-renders the same page after delete'
  end
end```
assistant