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

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 }