Ensure hashes can be passed to attributes using `composed_of`

This behavior was broken by 36e9be85. When the value is assigned
directly, either through mass assignment or directly assigning a hash,
the hash gets passed through to this writer method directly. While this
is intended to handle certain cases, when an explicit converter has been
provided, we should continue to use that instead. The positioning of the
added guard caused the new behavior to override that case.

Fixes #25210

1 files changed, 5 insertions, 4 deletions

diff --git a/activerecord/lib/active_record/aggregations.rb b/activerecord/lib/active_record/aggregations.rb
index 3ff41ed81b..8bed5bca28 100644
--- a/activerecord/lib/active_record/aggregations.rb
+++ b/activerecord/lib/active_record/aggregations.rb
@@ -256,15 +256,16 @@ module ActiveRecord
         def writer_method(name, class_name, mapping, allow_nil, converter)
           define_method("#{name}=") do |part|
             klass = class_name.constantize
-            if part.is_a?(Hash)
-              raise ArgumentError unless part.size == part.keys.max
-              part = klass.new(*part.sort.map(&:last))
-            end
 
             unless part.is_a?(klass) || converter.nil? || part.nil?
               part = converter.respond_to?(:call) ? converter.call(part) : klass.send(converter, part)
             end
 
+            if part.is_a?(Hash)
+              raise ArgumentError unless part.size == part.keys.max
+              part = klass.new(*part.sort.map(&:last))
+            end
+
             if part.nil? && allow_nil
               mapping.each { |key, _| self[key] = nil }
               @aggregation_cache[name] = nil