Mimic Rails behavior for instance props and rendering (#81)

* Mimic some rails behavior by using instance variables as props, defaulting renders, and no renders at all

* fix specs that were affected by calling a method on a mocked controller

* code cleanup

* Dont magically provide props if props are manually specified, require instance props to be opt in

* Remove inertia_render helper and enable render inertia: true syntax

* remove leftover method from refactoring

Co-authored-by: Brandon Shar <[email protected]>

Author: BrandonShar

lib/inertia_rails/controller.rb

@@ -20,6 +20,21 @@ def inertia_share(**args, &block)
           InertiaRails.share_block(block) if block
         end
       end
+
+      def use_inertia_instance_props
+        before_action do
+          @_inertia_instance_props = true
+          @_inertia_skip_props = view_assigns.keys + ['_inertia_skip_props']
+        end
+      end
+    end
+
+    def default_render
+      if InertiaRails.default_render?
+        render(inertia: true)
+      else
+        super
+      end
     end
 
     def redirect_to(options = {}, response_options = {})
@@ -36,6 +51,11 @@ def redirect_back(fallback_location:, allow_other_host: true, **options)
       )
     end
 
+    def inertia_view_assigns
+      return {} unless @_inertia_instance_props
+      view_assigns.except(*@_inertia_skip_props)
+    end
+
     private
 
     def inertia_layout

lib/inertia_rails/inertia_rails.rb

@@ -32,6 +32,10 @@ def self.ssr_url
     Configuration.ssr_url
   end
 
+  def self.default_render?
+    Configuration.default_render
+  end 
+
   def self.html_headers
     self.threadsafe_html_headers || []
   end
@@ -66,6 +70,7 @@ module Configuration
     mattr_accessor(:version) { nil }
     mattr_accessor(:ssr_enabled) { false }
     mattr_accessor(:ssr_url) { 'http://localhost:13714' }
+    mattr_accessor(:default_render) { false }
 
     def self.evaluated_version
       self.version.respond_to?(:call) ? self.version.call : self.version

lib/inertia_rails/renderer.rb

@@ -7,12 +7,12 @@ class Renderer
     attr_reader :component, :view_data
 
     def initialize(component, controller, request, response, render_method, props:, view_data:)
-      @component = component
+      @component = component.is_a?(TrueClass) ? "#{controller.controller_path}/#{controller.action_name}" : component
       @controller = controller
       @request = request
       @response = response
       @render_method = render_method
-      @props = props || {}
+      @props = props || controller.inertia_view_assigns
       @view_data = view_data || {}
     end
 

spec/dummy/app/controllers/inertia_rails_mimic_controller.rb

@@ -0,0 +1,33 @@
+class InertiaRailsMimicController < ApplicationController
+  before_action :enable_inertia_default, only: :default_render_test
+  use_inertia_instance_props
+
+  def instance_props_test
+    @name = 'Brandon'
+    @sport = 'hockey'
+
+    render inertia: 'TestComponent'
+  end
+
+  def default_render_test
+    @name = 'Brian'
+  end
+
+  def provided_props_test
+    @name = 'Brian'
+
+    render inertia: 'TestComponent', props: {
+      sport: 'basketball',
+    }
+  end
+
+  def default_component_test
+    render inertia: true
+  end
+
+  def enable_inertia_default
+    InertiaRails.configure do |config|
+      config.default_render = true
+    end
+  end
+end

spec/dummy/config/routes.rb

@@ -28,5 +28,10 @@
   get 'lazy_props' => 'inertia_render_test#lazy_props'
   get 'non_inertiafied' => 'inertia_test#non_inertiafied'
 
+  get 'instance_props_test' => 'inertia_rails_mimic#instance_props_test'
+  get 'default_render_test' => 'inertia_rails_mimic#default_render_test'
+  get 'default_component_test' => 'inertia_rails_mimic#default_component_test'
+  get 'provided_props_test' => 'inertia_rails_mimic#provided_props_test'
+
   inertia 'inertia_route' => 'TestComponent'
 end

spec/inertia/rails_mimic_spec.rb

@@ -0,0 +1,38 @@
+require_relative '../../lib/inertia_rails/rspec'
+
+RSpec.describe 'rendering when mimicking rails behavior', type: :request, inertia: true do
+
+  context 'the props are provided by instance variables' do
+    it 'has the props' do
+      get instance_props_test_path
+
+      expect_inertia.to have_exact_props({'name' => 'Brandon', 'sport' => 'hockey'})
+    end
+  end
+
+  context 'props are explicitly provided' do
+    it 'only includes the provided props' do
+      get provided_props_test_path
+
+      expect_inertia.to have_exact_props({'sport': 'basketball'})
+    end
+  end
+
+  context 'no component name is provided' do
+    it 'has the correct derived component name' do
+      get default_component_test_path
+
+      expect_inertia.to render_component('inertia_rails_mimic/default_component_test')
+    end
+  end
+
+  context 'no render is done at all and default_render is enabled' do
+    it 'renders via inertia' do
+      get default_render_test_path
+
+      expect_inertia.to render_component('inertia_rails_mimic/default_render_test')
+      expect_inertia.to include_props({'name' => 'Brian'})
+    end
+  end
+end
+

spec/inertia/rendering_spec.rb

@@ -1,11 +1,13 @@
 RSpec.describe 'rendering inertia views', type: :request do
   subject { response.body }
 
+  let(:controller) { double('Controller', inertia_view_assigns: {})}
+
   context 'first load' do
-    let(:page) { InertiaRails::Renderer.new('TestComponent', '', request, response, '', props: nil, view_data: nil).send(:page) }
+    let(:page) { InertiaRails::Renderer.new('TestComponent', controller, request, response, '', props: nil, view_data: nil).send(:page) }
 
     context 'with props' do
-      let(:page) { InertiaRails::Renderer.new('TestComponent', '', request, response, '', props: {name: 'Brandon', sport: 'hockey'}, view_data: nil).send(:page) }
+      let(:page) { InertiaRails::Renderer.new('TestComponent', controller, request, response, '', props: {name: 'Brandon', sport: 'hockey'}, view_data: nil).send(:page) }
       before { get props_path }
 
       it { is_expected.to include inertia_div(page) }
@@ -37,7 +39,7 @@
   end
 
   context 'subsequent requests' do
-    let(:page) { InertiaRails::Renderer.new('TestComponent', '', request, response, '', props: {name: 'Brandon', sport: 'hockey'}, view_data: nil).send(:page) }
+    let(:page) { InertiaRails::Renderer.new('TestComponent', controller, request, response, '', props: {name: 'Brandon', sport: 'hockey'}, view_data: nil).send(:page) }
     let(:headers) { {'X-Inertia' => true} }
 
     before { get props_path, headers: headers }
@@ -62,7 +64,7 @@
 
   context 'partial rendering' do
     let (:page) {
-      InertiaRails::Renderer.new('TestComponent', '', request, response, '', props: { sport: 'hockey'}, view_data: nil).send(:page)
+      InertiaRails::Renderer.new('TestComponent', controller, request, response, '', props: { sport: 'hockey'}, view_data: nil).send(:page)
     }
     let(:headers) {{
       'X-Inertia' => true,
@@ -92,7 +94,7 @@
   context 'lazy prop rendering' do
     context 'on first load' do
       let (:page) {
-        InertiaRails::Renderer.new('TestComponent', '', request, response, '', props: { name: 'Brian'}, view_data: nil).send(:page)
+        InertiaRails::Renderer.new('TestComponent', controller, request, response, '', props: { name: 'Brian'}, view_data: nil).send(:page)
       }
       before { get lazy_props_path }
 
@@ -101,7 +103,7 @@
 
     context 'with a partial reload' do
       let (:page) {
-        InertiaRails::Renderer.new('TestComponent', '', request, response, '', props: { sport: 'basketball', level: 'worse than he believes', grit: 'intense'}, view_data: nil).send(:page)
+        InertiaRails::Renderer.new('TestComponent', controller, request, response, '', props: { sport: 'basketball', level: 'worse than he believes', grit: 'intense'}, view_data: nil).send(:page)
       }
       let(:headers) {{
         'X-Inertia' => true,