change add_concurrent_index function arguments

lib/gitlab/database/migration_helpers.rb

@@ -11,7 +11,7 @@ module Gitlab
       #     add_concurrent_index :users, :some_column
       #
       # See Rails' `add_index` for more info on the available arguments.
-      def add_concurrent_index(*args)
+      def add_concurrent_index(table_name, column_name, options = {})
         if transaction_open?
           raise 'add_concurrent_index can not be run inside a transaction, ' \
             'you can disable transactions by calling disable_ddl_transaction! ' \
@@ -19,14 +19,10 @@ module Gitlab
         end
 
         if Database.postgresql?
-          if args[2].present?
-            args[2].merge!({ algorithm: :concurrently })
-          else
-            args << { algorithm: :concurrently }
-          end
+          options = options.merge({ algorithm: :concurrently })
         end
 
-        add_index(*args)
+        add_index(table_name, column_name, options)
       end
 
       # Updates the value of a column in batches.

spec/lib/gitlab/database/migration_helpers_spec.rb

@@ -16,14 +16,21 @@ describe Gitlab::Database::MigrationHelpers, lib: true do
       end
 
       context 'using PostgreSQL' do
-        it 'creates the index concurrently' do
-          expect(Gitlab::Database).to receive(:postgresql?).and_return(true)
+        before { expect(Gitlab::Database).to receive(:postgresql?).and_return(true) }
 
+        it 'creates the index concurrently' do
           expect(model).to receive(:add_index).
             with(:users, :foo, algorithm: :concurrently)
 
           model.add_concurrent_index(:users, :foo)
         end
+
+        it 'creates unique index concurrently' do
+          expect(model).to receive(:add_index).
+            with(:users, :foo, { algorithm: :concurrently, unique: true })
+
+          model.add_concurrent_index(:users, :foo, unique: true)
+        end
       end
 
       context 'using MySQL' do
@@ -31,7 +38,7 @@ describe Gitlab::Database::MigrationHelpers, lib: true do
           expect(Gitlab::Database).to receive(:postgresql?).and_return(false)
 
           expect(model).to receive(:add_index).
-            with(:users, :foo)
+            with(:users, :foo, {})
 
           model.add_concurrent_index(:users, :foo)
         end