failing test for cached:true parameter in collections

lib/pbbuilder.rb

@@ -40,13 +40,17 @@ def method_missing(...)
     set!(...)
   end
 
+  def attributes!
+    @message.to_h
+  end
+
   def respond_to_missing?(field)
     [email protected](field.to_s)
   end
 
   def set!(field, *args, &block)
     name = field.to_s
-    descriptor = @message.class.descriptor.lookup(name)
+    descriptor = _descriptor_for_field(name)
     ::Kernel.raise ::ArgumentError, "Unknown field #{name}" if descriptor.nil?
 
     if block
@@ -72,10 +76,18 @@ def set!(field, *args, &block)
           arg.to_hash.each do |k, v|
             @message[name][k] = v
           end
-        elsif arg.respond_to?(:to_ary)
+        elsif arg.respond_to?(:to_ary) && !descriptor.type.eql?(:message)
           # pb.fields ["one", "two"]
           # Using concat so it behaves the same as _append_repeated
           @message[name].concat arg.to_ary
+        elsif arg.respond_to?(:to_ary) && descriptor.type.eql?(:message)
+          # pb.friends [Person.new(name: "Johnny Test"), Person.new(name: "Max Verstappen")]
+          # Concat another Protobuf message into parent Protobuf message (not ary of strings)
+
+          args.flatten.each do |obj|
+            # Creates a message from descriptor
+            @message[name].push descriptor.subtype.msgclass.new(obj)
+          end
         else
           # pb.fields "one"
           @message[name].push arg
@@ -118,7 +130,7 @@ def merge!(object)
     object.each_key do |key|
       next if object[key].respond_to?(:empty?) && object[key].empty?
 
-      descriptor = @message.class.descriptor.lookup(key.to_s)
+      descriptor = _descriptor_for_field(key)
       ::Kernel.raise ::ArgumentError, "Unknown field #{name}" if descriptor.nil?
 
       if descriptor.label == :repeated
@@ -184,6 +196,10 @@ def target!
 
   private
 
+  def _descriptor_for_field(field)
+    @message.class.descriptor.lookup(field.to_s)
+  end
+
   # Appends protobuf message with existing @message object
   #
   # @param name string

lib/pbbuilder/collection_renderer.rb

@@ -0,0 +1,87 @@
+
+require 'active_support/concern'
+require 'action_view'
+
+begin
+  require 'action_view/renderer/collection_renderer'
+rescue LoadError
+  require 'action_view/renderer/partial_renderer'
+end
+
+class Pbbuilder
+  module CollectionRenderable # :nodoc:
+    extend ActiveSupport::Concern
+
+    class_methods do
+      def supported?
+        superclass.private_method_defined?(:build_rendered_template) && self.superclass.private_method_defined?(:build_rendered_collection)
+      end
+    end
+
+    private
+
+    def build_rendered_template(content, template, layout = nil)
+      super(content || pb.attributes!, template)
+    end
+
+    def build_rendered_collection(templates, _spacer)
+      pb.set!(field, templates.map(&:body))
+    end
+
+    def pb
+      @options[:locals].fetch(:pb)
+    end
+
+    def field
+      @options[:locals].fetch(:field).to_s
+    end
+  end
+
+  if defined?(::ActionView::CollectionRenderer)
+    # Rails 6.1 support:
+    class CollectionRenderer < ::ActionView::CollectionRenderer # :nodoc:
+      include CollectionRenderable
+
+      def initialize(lookup_context, options, &scope)
+        super(lookup_context, options)
+        @scope = scope
+      end
+
+      private
+        def collection_with_template(view, template, layout, collection)
+          super(view, template, layout, collection)
+        end
+    end
+  else
+    # Rails 6.0 support:
+    class CollectionRenderer < ::ActionView::PartialRenderer # :nodoc:
+      include CollectionRenderable
+
+      def initialize(lookup_context, options, &scope)
+        super(lookup_context)
+        @options = options
+        @scope = scope
+      end
+
+      def render_collection_with_partial(collection, partial, context, block)
+        render(context, @options.merge(collection: collection, partial: partial), block)
+      end
+
+      private
+        def collection_without_template(view)
+          super(view)
+        end
+
+        def collection_with_template(view, template)
+          super(view, template)
+        end
+    end
+  end
+
+  class EnumerableCompat < ::SimpleDelegator
+    # Rails 6.1 requires this.
+    def size(*args, &block)
+      __getobj__.count(*args, &block)
+    end
+  end
+end

lib/pbbuilder/pbbuilder.rb

@@ -1,9 +1,3 @@
 # frozen_string_literal: true
 
-Pbbuilder = Class.new(begin
-  require 'active_support/proxy_object'
-  ActiveSupport::ProxyObject
-rescue LoadError
-  require 'active_support/basic_object'
-  ActiveSupport::BasicObject
-end)
+Pbbuilder = Class.new(Object)

lib/pbbuilder/template.rb

@@ -1,5 +1,7 @@
 # frozen_string_literal: true
 
+require 'pbbuilder/collection_renderer'
+
 # PbbuilderTemplate is an extension of Pbbuilder to be used as a Rails template
 # It adds support for partials.
 class PbbuilderTemplate < Pbbuilder
@@ -37,6 +39,23 @@ def set!(field, *args, **kwargs, &block)
         super(field, *args) do |element|
           _set_inline_partial(element, kwargs)
         end
+      elsif kwargs.has_key?(:collection) && kwargs.has_key?(:as)
+        # pb.friends partial: "racers/racer", as: :racer, collection: [Racer.new(1, "Johnny Test", []), Racer.new(2, "Max Verstappen", [])]
+        # collection renderer
+        options = kwargs.deep_dup
+
+        options.reverse_merge! locals: options.except(:partial, :as, :collection, :cached)
+        options.reverse_merge! ::PbbuilderTemplate.template_lookup_options
+
+        collection = options[:collection] || []
+        partial = options[:partial]
+        options[:locals].merge!(pb: self)
+        options[:locals].merge!(field: field)
+
+        result = CollectionRenderer
+            .new(@context.lookup_context, options) { |&block| _scope(message[field.to_s],&block) }
+            .render_collection_with_partial(collection, partial, @context, nil)
+
       else
         # pb.best_friend partial: "person", person: @best_friend
         # Call set! as a submessage, passing in the kwargs as partial options

test/pbbuilder_template_test.rb

@@ -30,11 +30,26 @@ class PbbuilderTemplateTest < ActiveSupport::TestCase
     assert_equal "hello", result.name
   end
 
+  test "collections render" do
+    result = render('pb.friends partial: "racers/racer", as: :racer, collection: [Racer.new(1, "Johnny Test", []), Racer.new(2, "Max Verstappen", [])]')
+
+    assert_equal 2, result.friends.count
+  end
+
   test "partial by name with top-level locals" do
     result = render('pb.partial! "partial", name: "hello"')
     assert_equal "hello", result.name
   end
 
+  test "partial by name with caching" do
+    skip()
+    assert_difference('Rails.cache.instance_variable_get(:@data).size') do
+      result = render('pb.partial! "partial", name: "hello", cached: true')
+
+      assert_equal "hello", result.name
+    end
+  end
+
   test "submessage partial" do
     other_racer = Racer.new(2, "Max Verstappen", [])
     racer = Racer.new(123, "Chris Harris", [], other_racer)