block2.rb

describe Post do
  let(:api_client) { double(fetch_comments: []) }
  subject(:post) { Post.new(api_client: api_client) }

  describe '#comments' do
    it 'only fetches the approved comments by default' do
      expect(api_client)
        .to receive(:fetch_comments)
        .with(a_hash_including(approved: true))
        .once
        .and_call_original

      post.comments
    end

    it 'only fetches the unread comments by default' do
      expect(api_client)
        .to receive(:fetch_comments)
        .with(a_hash_including(status: :unread))
        .once
        .and_call_original

      post.comments
    end

    # ...
  end
end