feat(ServerRendering) add WebpackerManifestContainer

Author: rmosolgo

lib/react/server_rendering/sprockets_renderer.rb

@@ -1,5 +1,6 @@
 require "react/server_rendering/environment_container"
 require "react/server_rendering/manifest_container"
+require "react/server_rendering/webpacker_manifest_container"
 require "react/server_rendering/yaml_manifest_container"
 
 module React
@@ -57,19 +58,7 @@ class << self
       #
       # @return [#find_asset(logical_path)] An object that returns asset contents by logical path
       def asset_container
-        @asset_container ||= if self.class.asset_container_class.present?
-          self.class.asset_container_class.new
-        elsif assets_precompiled? && ManifestContainer.compatible?
-          ManifestContainer.new
-        elsif assets_precompiled? && YamlManifestContainer.compatible?
-          YamlManifestContainer.new
-        else
-          EnvironmentContainer.new
-        end
-      end
-
-      def assets_precompiled?
-        !::Rails.application.config.assets.compile
+        @asset_container ||= asset_container_class.new
       end
 
       private
@@ -97,6 +86,29 @@ def render_function(opts)
       def prepare_props(props)
         props.is_a?(String) ? props : props.to_json
       end
+
+      def assets_precompiled?
+        !::Rails.application.config.assets.compile
+      end
+
+      def asset_container_class
+        if self.class.asset_container_class.present?
+          self.class.asset_container_class
+        elsif assets_precompiled?
+          if WebpackerManifestContainer.compatible?
+            WebpackerManifestContainer
+          elsif ManifestContainer.compatible?
+            ManifestContainer
+          elsif YamlManifestContainer.compatible?
+            YamlManifestContainer
+          else
+            # Even though they are precompiled, we can't find them :S
+            EnvironmentContainer
+          end
+        else
+          EnvironmentContainer
+        end
+      end
     end
   end
 end

lib/react/server_rendering/webpacker_manifest_container.rb

@@ -0,0 +1,21 @@
+module React
+  module ServerRendering
+    # Get a compiled file from Webpacker
+    class WebpackerManifestContainer
+      def find_asset(logical_path)
+        asset_path = Webpacker::Manifest.lookup(logical_path) # raises if not found
+        full_path = File.join(
+          # TODO: using `.parent` here won't work for nonstandard configurations
+          Webpacker::Configuration.output_path.parent,
+          asset_path
+        )
+        # TODO: webpacker-dev-server points these at localhost:8080
+        File.read(full_path)
+      end
+
+      def self.compatible?
+        defined?(Webpacker)
+      end
+    end
+  end
+end

lib/react/server_rendering/yaml_manifest_container.rb

@@ -1,6 +1,6 @@
 module React
   module ServerRendering
-    # Get asset content by reading the compiled file from disk using the generated maniftest.yml file
+    # Get asset content by reading the compiled file from disk using the generated manifest.yml file
     #
     # This is good for Rails production when assets are compiled to public/assets
     # but sometimes, they're compiled to other directories (or other servers)

test/react/rails/webpacker_test.rb

@@ -1,6 +1,5 @@
 require 'test_helper'
 
-
 WebpackerHelpers.when_webpacker_available do
   class ReactRailsWebpackerTest < ActionDispatch::IntegrationTest
     include Capybara::DSL

test/react/server_rendering/webpacker_manifest_container_test.rb

@@ -0,0 +1,14 @@
+require "test_helper"
+
+WebpackerHelpers.when_webpacker_available do
+  class WebpackerManifestContainerTest < ActiveSupport::TestCase
+    test "it loads JS from the webpacker container" do
+      container = React::ServerRendering::WebpackerManifestContainer.new
+      js_file = container.find_asset("application.js")
+      # Main file:
+      assert_includes js_file, "ReactRailsUJS.loadContext(ctx)"
+      # Bundled dependencies:
+      assert_includes js_file, "ExportDefaultComponent"
+    end
+  end
+end