spec/rubocop/cop/usage_data/distinct_count_by_large_foreign_key_spec.rb


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# frozen_string_literal: true

require 'fast_spec_helper'
require 'rubocop'

require_relative '../../../../rubocop/cop/usage_data/distinct_count_by_large_foreign_key'

RSpec.describe RuboCop::Cop::UsageData::DistinctCountByLargeForeignKey do
  let(:allowed_foreign_keys) { [:author_id, :user_id, :'merge_requests.target_project_id'] }
  let(:msg) { 'Avoid doing `distinct_count` on foreign keys for large tables having above 100 million rows.' }
  let(:config) do
    RuboCop::Config.new('UsageData/DistinctCountByLargeForeignKey' => {
                          'AllowedForeignKeys' => allowed_foreign_keys
                        })
  end

  subject(:cop) { described_class.new(config) }

  context 'when counting by disallowed key' do
    it 'registers an offense' do
      expect_offense(<<~CODE)
        distinct_count(Issue, :creator_id)
        ^^^^^^^^^^^^^^ #{msg}
      CODE
    end

    it 'does not register an offense when batch is false' do
      expect_no_offenses('distinct_count(Issue, :creator_id, batch: false)')
    end

    it 'registers an offense when batch is true' do
      expect_offense(<<~CODE)
        distinct_count(Issue, :creator_id, batch: true)
        ^^^^^^^^^^^^^^ #{msg}
      CODE
    end
  end

  context 'when calling by allowed key' do
    it 'does not register an offense with symbol' do
      expect_no_offenses('distinct_count(Issue, :author_id)')
    end

    it 'does not register an offense with string' do
      expect_no_offenses("distinct_count(Issue, 'merge_requests.target_project_id')")
    end
  end
end