Merge pull request #30 from rightscale/rendering_nil_subobjects

Fix corner case bug rendering nil subjects

.travis.yml

@@ -2,7 +2,7 @@ language: ruby
 cache: bundler
 sudo: false
 rvm:
-  - 2.2.3
+  - 2.2.5
   - 2.3.1
 script:
   - bundle exec rspec spec

CHANGELOG.md

@@ -4,6 +4,7 @@
 
 * Include Attributor::Dumpable in Blueprint, so it renders (semi) correctly if
   rendered with just `true` specified for fields.
+* Fix bug rendering subobjects with nil values (manifested when `include_nil: true` there’s an explicit subsection of fields)
 
 ## 3.2
 

lib/praxis-blueprints/blueprint.rb

@@ -337,11 +337,11 @@ def validate(context = Attributor::DEFAULT_ROOT_CONTEXT)
         if value.respond_to?(:validating) # really, it's a thing with sub-attributes
           next if value.validating
         end
-        errors.push(*sub_attribute.validate(value, sub_context))
+        errors.concat(sub_attribute.validate(value, sub_context))
       end
       self.class.attribute.type.requirements.each do |req|
         validation_errors = req.validate(keys_with_values, context)
-        errors.push(*validation_errors) unless validation_errors.empty?
+        errors.concat(validation_errors) unless validation_errors.empty?
       end
       errors
     ensure

lib/praxis-blueprints/config_hash.rb

@@ -17,7 +17,11 @@ def to_hash
       @hash
     end
 
-    def method_missing(name, value, *rest, &block)
+    def respond_to_missing?(_method_name, _include_private = false)
+      true
+    end
+
+    def method_missing(name, value, *rest, &block) # rubocop:disable Style/MethodMissing
       if (existing = @hash[name])
         if block
           existing << [value, block]

lib/praxis-blueprints/field_expander.rb

@@ -108,7 +108,7 @@ def expand_with_member_attribute(object, fields = true)
       new_fields = fields.is_a?(Array) ? fields[0] : fields
 
       result = [expand(object.member_attribute.type, new_fields)]
-      history[object][fields].push(*result)
+      history[object][fields].concat(result)
 
       result
     end

lib/praxis-blueprints/renderer.rb

@@ -79,7 +79,10 @@ def _render(object, fields, view = nil, context: Attributor::DEFAULT_ROOT_CONTEX
             raise Attributor::DumpError, context: context, name: key, type: object.class, original_exception: e
           end
 
-          next if value.nil? && !include_nil
+          if value.nil?
+            hash[key] = nil if self.include_nil
+            next
+          end
 
           if subfields == true
             hash[key] = case value

spec/praxis-blueprints/config_hash_spec.rb

@@ -0,0 +1,64 @@
+# frozen_string_literal: true
+require File.expand_path(File.dirname(__FILE__) + '/../spec_helper')
+
+describe Praxis::ConfigHash do
+  subject(:instance) { Praxis::ConfigHash.new(hash, &block) }
+  let(:hash) { { one: ['existing'], two: 'dos' } }
+  let(:block) do
+    proc { 'abc' }
+  end
+
+  context 'initialization' do
+    it 'saves the passed hash' do
+      expect(subject.hash).to be(hash)
+    end
+  end
+
+  context '.from' do
+    subject(:instance) { Praxis::ConfigHash.from(hash, &block) }
+    it 'returns an instance' do
+      expect(subject).to be_kind_of(Praxis::ConfigHash)
+      expect(subject.hash).to be(hash)
+    end
+  end
+
+  context '#to_hash' do
+    let(:block) do
+      proc { hash['i_was'] = 'here' }
+    end
+    it 'evaluates the block and returns the resulting hash' do
+      expect(subject.to_hash).to eq(subject.hash)
+      expect(subject.hash['i_was']).to eq('here')
+    end
+  end
+
+  context '#method_missing' do
+    context 'when keys do not exist in the hash key' do
+      it 'sets a single value to the hash' do
+        subject.some_name 'someval'
+        expect(subject.hash[:some_name]).to eq('someval')
+      end
+      it 'sets a multiple values to the hash key' do
+        subject.some_name 'someval', 'other1', 'other2'
+        expect(subject.hash[:some_name]).to include('someval', 'other1', 'other2')
+      end
+    end
+    context 'when keys already exist in the hash key' do
+      it 'adds one value to the hash' do
+        subject.one'newval'
+        expect(subject.hash[:one]).to match_array(%w(existing newval))
+      end
+      it 'adds multiple values to the hash key' do
+        subject.one 'newval', 'other1', 'other2'
+        expect(subject.hash[:one]).to match_array(%w(existing newval other1 other2))
+      end
+      context 'when passing a value and a block' do
+        let(:my_block) { proc {} }
+        it 'adds the tuple to the hash key' do
+          subject.one 'val', &my_block
+          expect(subject.hash[:one]).to include(['val', my_block])
+        end
+      end
+    end
+  end
+end

spec/praxis-blueprints/renderer_spec.rb

@@ -100,6 +100,7 @@
 
   context 'with include_nil: true' do
     let(:renderer) { Praxis::Renderer.new(include_nil: true) }
+    let(:address) { nil }
 
     it 'renders attributes with nil values' do
       output.should have_key :email
@@ -108,6 +109,11 @@
       output.should have_key :work_address
       output[:work_address].should be nil
     end
+
+    it 'renders nil directly for nil subobjects' do
+      output.should have_key :address
+      output[:address].should be nil
+    end
   end
 
   context '#render_collection' do