Handle special-case of Array serializer with unserializable elements

Author: bf4

lib/action_controller/serialization.rb

@@ -42,10 +42,9 @@ def use_adapter?
           @_serializer_opts[:scope] ||= serialization_scope
           @_serializer_opts[:scope_name] = _serialization_scope
 
-          object   = serializer.new(resource, @_serializer_opts)
-
-          if serializer == ActiveModel::Serializer.config.array_serializer
-            resource = ActiveModel::Serializer::Adapter.create(object, @_adapter_opts) unless object.objects.all? {|i| i.nil?}
+          begin
+            object   = serializer.new(resource, @_serializer_opts)
+          rescue ActiveModel::Serializer::ArraySerializer::Error
           else
             resource = ActiveModel::Serializer::Adapter.create(object, @_adapter_opts)
           end

lib/active_model/serializer.rb

@@ -211,7 +211,7 @@ def each_association(&block)
               association_value,
               options.except(:serializer).merge(serializer_from_options(association_options))
             )
-          rescue NoMethodError
+          rescue ActiveModel::Serializer::ArraySerializer::Error
             # 1. Failure to serialize an element in a collection, e.g. [ {hi: "Steve" } ] will fail
             #    with NoMethodError when the ArraySerializer finds no serializer for the hash { hi: "Steve" },
             #    and tries to call new on that nil.

lib/active_model/serializer/array_serializer.rb

@@ -1,6 +1,7 @@
 module ActiveModel
   class Serializer
     class ArraySerializer
+      Error = Class.new(StandardError)
       include Enumerable
       delegate :each, to: :@objects
 
@@ -14,7 +15,9 @@ def initialize(objects, options = {})
             ActiveModel::Serializer.serializer_for(object)
           )
 
-          unless serializer_class.nil?
+          if serializer_class.nil?
+            fail Error, "No serializer found for object: #{object.inspect}"
+          else
             serializer_class.new(object, options.except(:serializer))
           end
         end