1 files changed, 38 insertions, 0 deletions
diff --git a/spec/rubocop/cop/usage_data/distinct_count_by_large_foreign_key_spec.rb b/spec/rubocop/cop/usage_data/distinct_count_by_large_foreign_key_spec.rb
new file mode 100644
index 00000000000..db931c50bdf
--- /dev/null
+++ b/spec/rubocop/cop/usage_data/distinct_count_by_large_foreign_key_spec.rb
@@ -0,0 +1,38 @@
+# frozen_string_literal: true
+
+require 'fast_spec_helper'
+
+require 'rubocop'
+require 'rubocop/rspec/support'
+
+require_relative '../../../../rubocop/cop/usage_data/distinct_count_by_large_foreign_key'
+
+RSpec.describe RuboCop::Cop::UsageData::DistinctCountByLargeForeignKey, type: :rubocop do
+  include CopHelper
+
+  let(:allowed_foreign_keys) { %i[author_id user_id] }
+
+  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 'register an offence' do
+      inspect_source('distinct_count(Issue, :creator_id)')
+
+      expect(cop.offenses.size).to eq(1)
+    end
+  end
+
+  context 'when calling by allowed key' do
+    it 'does not register an offence' do
+      inspect_source('distinct_count(Issue, :author_id)')
+
+      expect(cop.offenses).to be_empty
+    end
+  end
+end