Fix `quote_default_expression` for UUID with array default

Fixes #30539.

2 files changed, 11 insertions, 1 deletions

diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/quoting.rb b/activerecord/lib/active_record/connection_adapters/postgresql/quoting.rb
index fc458d0c73..a0a22ba0f1 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/quoting.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/quoting.rb
@@ -64,7 +64,7 @@ module ActiveRecord
         def quote_default_expression(value, column) # :nodoc:
           if value.is_a?(Proc)
             value.call
-          elsif column.type == :uuid && /\(\)/.match?(value)
+          elsif column.type == :uuid && value.is_a?(String) && /\(\)/.match?(value)
             value # Does not quote function default values for UUID columns
           elsif column.respond_to?(:array?)
             value = type_cast_from_column(column, value)
diff --git a/activerecord/test/cases/adapters/postgresql/uuid_test.rb b/activerecord/test/cases/adapters/postgresql/uuid_test.rb
index 76cb1bc354..8ba5132a8f 100644
--- a/activerecord/test/cases/adapters/postgresql/uuid_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/uuid_test.rb
@@ -76,6 +76,16 @@ class PostgresqlUUIDTest < ActiveRecord::PostgreSQLTestCase
     assert_nil column.default
   end
 
+  def test_add_column_with_default_array
+    connection.add_column :uuid_data_type, :thingy, :uuid, array: true, default: []
+
+    UUIDType.reset_column_information
+    column = UUIDType.columns_hash["thingy"]
+
+    assert column.array?
+    assert [], column.default
+  end
+
   def test_data_type_of_uuid_types
     column = UUIDType.columns_hash["guid"]
     assert_equal :uuid, column.type