Fix server-side rendering in development mode

lib/react/rails/railtie.rb

@@ -56,13 +56,15 @@ class Railtie < ::Rails::Railtie
       config.after_initialize do |app|
         # Server Rendering
         # Concat component_filenames together for server rendering
-        app.config.react.components_js = app.config.react.component_filenames.map do |filename|
-          app.assets[filename].to_s
-        end.join(";")
+        app.config.react.components_js = lambda {
+          app.config.react.component_filenames.map do |filename|
+            app.assets[filename].to_s
+          end.join(";")
+        }
 
         do_setup = lambda do
           cfg = app.config.react
-          React::Renderer.setup!( cfg.react_js.call, cfg.components_js,
+          React::Renderer.setup!( cfg.react_js, cfg.components_js,
                                 {:size => cfg.size, :timeout => cfg.timeout})
         end
 

lib/react/renderer.rb

@@ -10,6 +10,7 @@ def self.setup!(react_js, components_js, args={})
       @@react_js = react_js
       @@components_js = components_js
       @@pool.shutdown{} if @@pool
+      reset_combined_js!
       @@pool = ConnectionPool.new(:size => args[:size]||10, :timeout => args[:timeout]||20) { self.new }
     end
 
@@ -19,8 +20,8 @@ def self.render(component, args={})
       end
     end
 
-    def self.combined_js
-      @@combined_js ||= <<-CODE
+    def self.setup_combined_js
+      <<-CODE
         var global = global || this;
 
         var console = global.console || {};
@@ -30,12 +31,20 @@ def self.combined_js
           }
         });
 
-        #{@@react_js};
+        #{@@react_js.call};
         React = global.React;
-        #{@@components_js};
+        #{@@components_js.call};
       CODE
     end
 
+    def self.reset_combined_js!
+      @@combined_js = setup_combined_js
+    end
+
+    def self.combined_js
+      @@combined_js
+    end
+
     def context
       @context ||= ExecJS.compile(self.class.combined_js)
     end

test/helper_files/TodoListWithUpdates.js.jsx

@@ -0,0 +1,22 @@
+/** @jsx React.DOM */
+
+TodoList = React.createClass({
+  getInitialState: function() {
+    return({mounted: "nope"});
+  },
+  componentWillMount: function() {
+    this.setState({mounted: 'yep'});
+  },
+  render: function() {
+    return (
+      <ul>
+        <li>Updated</li>
+        <li id='status'>{this.state.mounted}</li>
+        {this.props.todos.map(function(todo, i) {
+          return (<Todo key={i} todo={todo} />)
+        })}
+      </ul>
+    )
+  }
+})
+

test/react_test.rb

@@ -31,6 +31,8 @@ class ReactTest < ActionDispatch::IntegrationTest
 
     assert_response :success
     assert_equal "'test_confirmation_token_react_content';\n", @response.body
+
+    React::Renderer.reset_combined_js!
   end
 
 end

test/server_rendered_html_test.rb

@@ -0,0 +1,37 @@
+require 'test_helper'
+require 'fileutils'
+
+class ServerRenderedHtmlTest  < ActionDispatch::IntegrationTest
+  # Rails' asset pipeline has trouble picking up changes to files if they happen too fast.
+  # By sleeping for a little bit at certain points, we can make sure that rails notices the
+  # change in the file mtime, and calls our renderer setup functions appropriately
+  def wait_to_ensure_asset_pipeline_detects_changes
+    sleep(1)
+  end
+
+  test 'react server rendering reloads jsx after changes to the jsx files' do
+    file_with_updates = File.expand_path('../helper_files/TodoListWithUpdates.js.jsx', __FILE__)
+    file_without_updates = File.expand_path('../helper_files/TodoListWithoutUpdates.js.jsx', __FILE__)
+    app_file = File.expand_path('../dummy/app/assets/javascripts/components/TodoList.js.jsx', __FILE__)
+
+    FileUtils.cp app_file, file_without_updates
+    FileUtils.touch app_file
+
+    begin
+      get '/server/1'
+      refute_match 'Updated', response.body
+
+      wait_to_ensure_asset_pipeline_detects_changes
+      FileUtils.cp file_with_updates, app_file
+      FileUtils.touch app_file
+
+      get '/server/1'
+      assert_match 'Updated', response.body
+    ensure
+      # if we have a test failure, we want to make sure that we revert the dummy file
+      wait_to_ensure_asset_pipeline_detects_changes
+      FileUtils.mv file_without_updates, app_file
+      FileUtils.touch app_file
+    end
+  end
+end

test/test_helper.rb

@@ -22,3 +22,7 @@
 if ActiveSupport::TestCase.method_defined?(:fixture_path=)
   ActiveSupport::TestCase.fixture_path = File.expand_path("../fixtures", __FILE__)
 end
+
+def wait_for_turbolinks_to_be_available
+  sleep(1)
+end

test/view_helper_test.rb

@@ -62,10 +62,14 @@ class ViewHelperTest < ActionDispatch::IntegrationTest
     page.execute_script('history.back();')
     assert page.has_content?('Hello Alice')
 
+    wait_for_turbolinks_to_be_available()
+
     # Try Turbolinks javascript API.
     page.execute_script('Turbolinks.visit("/pages/2");')
     assert page.has_content?('Hello Alice')
 
+    wait_for_turbolinks_to_be_available()
+
     page.execute_script('Turbolinks.visit("/pages/1");')
     assert page.has_content?('Hello Bob')