Add coverage for `CLI::Accounts#fix_duplications` task (#30639)

app/models/account.rb

@@ -145,6 +145,7 @@ class Account < ApplicationRecord
   scope :with_username, ->(value) { where arel_table[:username].lower.eq(value.to_s.downcase) }
   scope :with_domain, ->(value) { where arel_table[:domain].lower.eq(value&.to_s&.downcase) }
   scope :without_memorial, -> { where(memorial: false) }
+  scope :duplicate_uris, -> { select(:uri, Arel.star.count).group(:uri).having(Arel.star.count.gt(1)) }
 
   after_update_commit :trigger_update_webhooks
 

lib/mastodon/cli/accounts.rb

@@ -252,7 +252,7 @@ module Mastodon::CLI
       domain configuration.
     LONG_DESC
     def fix_duplicates
-      Account.remote.select(:uri, 'count(*)').group(:uri).having('count(*) > 1').pluck(:uri).each do |uri|
+      Account.remote.duplicate_uris.pluck(:uri).each do |uri|
         say("Duplicates found for #{uri}")
         begin
           ActivityPub::FetchRemoteAccountService.new.call(uri) unless dry_run?

spec/lib/mastodon/cli/accounts_spec.rb

@@ -613,6 +613,25 @@ describe Mastodon::CLI::Accounts do
     end
   end
 
+  describe '#fix_duplicates' do
+    let(:action) { :fix_duplicates }
+    let(:service_double) { instance_double(ActivityPub::FetchRemoteAccountService, call: nil) }
+    let(:uri) { 'https://host.example/same/value' }
+
+    context 'when there are duplicate URI accounts' do
+      before do
+        Fabricate.times(2, :account, domain: 'host.example', uri: uri)
+        allow(ActivityPub::FetchRemoteAccountService).to receive(:new).and_return(service_double)
+      end
+
+      it 'finds the duplicates and calls fetch remote account service' do
+        expect { subject }
+          .to output_results('Duplicates found')
+        expect(service_double).to have_received(:call).with(uri)
+      end
+    end
+  end
+
   describe '#backup' do
     let(:action) { :backup }