Correctly handle array columns with defaults in the schema dumper

If the subtype provides custom schema dumping behavior, we need to defer
to it. We purposely choose not to handle any values other than an array
(which technically should only ever be `nil`, but I'd rather code
defensively here).

Fixes #20515.

1 files changed, 5 insertions, 0 deletions

diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/array.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/array.rb
index 3de794f797..25961a9869 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/oid/array.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/array.rb
@@ -45,6 +45,11 @@ module ActiveRecord
               delimiter == other.delimiter
           end
 
+          def type_cast_for_schema(value)
+            return super unless value.is_a?(::Array)
+            "[" + value.map { |v| subtype.type_cast_for_schema(v) }.join(", ") + "]"
+          end
+
           private
 
           def type_cast_array(value, method)