Replace fail/rescue CollectionSerializer::NoSerializerError with thro…

…w/catch :no_serializer

CHANGELOG.md

@@ -6,6 +6,7 @@ Breaking changes:
 
 Features:
 - [#1426](https://github.com/rails-api/active_model_serializers/pull/1426) Add ActiveModelSerializers.config.default_includes (@empact)
+- [TBD](TBD) Replace raising/rescuing `CollectionSerializer::NoSerializerError`, throw/catch `:no_serializer`. (@bf4)
 
 Fixes:
 - [#1710](https://github.com/rails-api/active_model_serializers/pull/1710) Prevent association loading when `include_data` option

docs/ARCHITECTURE.md

@@ -15,7 +15,7 @@ It requires an adapter to transform its attributes into a JSON document; it cann
 It may be useful to think of it as a
 [presenter](http://blog.steveklabnik.com/posts/2011-09-09-better-ruby-presenters).
 
-The **`ActiveModel::ArraySerializer`** represent a collection of resources as serializers
+The **`ActiveModel::CollectionSerializer`** represent a collection of resources as serializers
 and, if there is no serializer, primitives.
 
 The **`ActiveModel::Adapter`** describes the structure of the JSON document generated from a
@@ -42,10 +42,9 @@ it is not modified.
 Internally, if no serializer can be found in the controller, the resource is not decorated by
 ActiveModelSerializers.
 
-If the collection serializer (ArraySerializer) cannot
-identify a serializer for a resource in its collection, it raises [`NoSerializerError`](https://github.com/rails-api/active_model_serializers/issues/1191#issuecomment-142327128)
-which is rescued in `ActiveModel::Serializer::Reflection#build_association` which sets
-the association value directly:
+If the collection serializer (CollectionSerializer) cannot
+identify a serializer for a resource in its collection, it throws [`:no_serializer`](https://github.com/rails-api/active_model_serializers/issues/1191#issuecomment-142327128).
+For example, when caught by `Reflection#build_association`, the association value is set directly:
 
 ```ruby
 reflection_options[:virtual_value] = association_value.try(:as_json) || association_value
@@ -85,8 +84,8 @@ Details:
   1. The serializer and adapter are created as
     1. `serializer_instance = serializer.new(resource, serializer_opts)`
     2. `adapter_instance = ActiveModel::Serializer::Adapter.create(serializer_instance, adapter_opts)`
-1. **ActiveModel::Serializer::ArraySerializer#new**
-  1. If the `serializer_instance` was a `ArraySerializer` and the `:serializer` serializer_opts
+1. **ActiveModel::Serializer::CollectionSerializer#new**
+  1. If the `serializer_instance` was a `CollectionSerializer` and the `:serializer` serializer_opts
     is present, then [that serializer is passed into each resource](https://github.com/rails-api/active_model_serializers/blob/a54d237e2828fe6bab1ea5dfe6360d4ecc8214cd/lib/active_model/serializer/array_serializer.rb#L14-L16).
 1. **ActiveModel::Serializer#attributes** is used by the adapter to get the attributes for
   resource as defined by the serializer.

lib/active_model/serializer/collection_serializer.rb

@@ -1,7 +1,6 @@
 module ActiveModel
   class Serializer
     class CollectionSerializer
-      NoSerializerError = Class.new(StandardError)
       include Enumerable
       delegate :each, to: :@serializers
 
@@ -15,8 +14,9 @@ def initialize(resources, options = {})
         @serializers = resources.map do |resource|
           serializer_class = options.fetch(:serializer) { serializer_context_class.serializer_for(resource) }
 
-          if serializer_class.nil? # rubocop:disable Style/GuardClause
-            fail NoSerializerError, "No serializer found for resource: #{resource.inspect}"
+          if serializer_class.nil?
+            ActiveModelSerializers.logger.debug "No serializer found for resource: #{resource.inspect}"
+            throw :no_serializer
           else
             serializer_class.new(resource, options.except(:serializer))
           end

lib/active_model/serializer/reflection.rb

@@ -113,12 +113,13 @@ def build_association(subject, parent_serializer_options)
         reflection_options[:include_data] = @_include_data
 
         if serializer_class
-          begin
-            serializer = serializer_class.new(
+          serializer = catch :no_serializer do
+            serializer_class.new(
               association_value,
               serializer_options(subject, parent_serializer_options, reflection_options)
             )
-          rescue ActiveModel::Serializer::CollectionSerializer::NoSerializerError
+          end
+          if serializer.nil?
             reflection_options[:virtual_value] = association_value.try(:as_json) || association_value
           end
         elsif !association_value.nil? && !association_value.instance_of?(Object)

lib/active_model_serializers/serializable_resource.rb

@@ -38,9 +38,10 @@ def adapter
 
     def find_adapter
       return resource unless serializer?
-      ActiveModelSerializers::Adapter.create(serializer_instance, adapter_opts)
-    rescue ActiveModel::Serializer::CollectionSerializer::NoSerializerError
-      resource
+      adapter = catch :no_serializer do
+        ActiveModelSerializers::Adapter.create(serializer_instance, adapter_opts)
+      end
+      adapter || resource
     end
 
     def serializer_instance