fix: Ruby 3.4 compat — remove strip_heredoc, add missing GitUtils require

CHANGELOG.md

@@ -25,6 +25,12 @@ After a release, run `/update-changelog` in Claude Code to analyze commits, writ
 
 ### [Unreleased]
 
+#### Fixed
+
+- **Ruby 3.4 compatibility for heredocs**: Replaced legacy `strip_heredoc` usage with native squiggly heredocs (`<<~`) and removed redundant chaining where indentation is already normalized by Ruby. [PR 2599](https://github.com/shakacode/react_on_rails/pull/2599) by [justin808](https://github.com/justin808).
+- **Fix install generator load path for `ReactOnRails::GitUtils`**: Added an explicit `require "react_on_rails/git_utils"` so generator execution does not rely on broader app boot side effects for this constant to be available. [PR 2599](https://github.com/shakacode/react_on_rails/pull/2599) by [justin808](https://github.com/justin808).
+- **`server_render_js` now handles non-Error throws safely**: Defensive error serialization now supports thrown primitives and `null` values without raising secondary `TypeError` exceptions while building SSR error payloads. [PR 2599](https://github.com/shakacode/react_on_rails/pull/2599) by [justin808](https://github.com/justin808).
+
 ### [16.4.0.rc.9] - 2026-03-12
 
 #### Improved

react_on_rails/lib/generators/react_on_rails/base_generator.rb

@@ -183,7 +183,7 @@ def append_to_spec_rails_helper
         add_configure_minitest_to_compile_assets(test_helper) if File.exist?(test_helper)
       end
 
-      CONFIGURE_RSPEC_TO_COMPILE_ASSETS = <<-STR.strip_heredoc
+      CONFIGURE_RSPEC_TO_COMPILE_ASSETS = <<~STR
         RSpec.configure do |config|
           # Ensure that if we are running js tests, we are using latest webpack assets
           # This will use the defaults of :js and :server_rendering meta tags
@@ -193,7 +193,7 @@ def append_to_spec_rails_helper
         end
       STR
 
-      CONFIGURE_MINITEST_TO_COMPILE_ASSETS = <<-STR.strip_heredoc
+      CONFIGURE_MINITEST_TO_COMPILE_ASSETS = <<~STR
         # Ensure that tests run against fresh webpack assets.
         ActiveSupport::TestCase.setup do
           ReactOnRails::TestHelper.ensure_assets_compiled

react_on_rails/lib/generators/react_on_rails/install_generator.rb

@@ -8,6 +8,8 @@
 require_relative "js_dependency_manager"
 require_relative "pro_setup"
 require_relative "rsc_setup"
+# Load-path require: git_utils lives under react_on_rails/lib, not relative to this generator directory.
+require "react_on_rails/git_utils"
 
 module ReactOnRails
   module Generators

react_on_rails/lib/react_on_rails/configuration.rb

@@ -408,10 +408,10 @@ def check_server_render_method_is_only_execjs
       return if server_render_method.blank? ||
                 server_render_method == "ExecJS"
 
-      msg = <<-MSG.strip_heredoc
-      Error configuring /config/initializers/react_on_rails.rb: invalid value for `config.server_render_method`.
-      If you wish to use a server render method other than ExecJS, contact [email protected]
-      for details.
+      msg = <<~MSG
+        Error configuring /config/initializers/react_on_rails.rb: invalid value for `config.server_render_method`.
+        If you wish to use a server render method other than ExecJS, contact [email protected]
+        for details.
       MSG
       raise ReactOnRails::Error, msg
     end

react_on_rails/lib/react_on_rails/helper.rb

@@ -210,43 +210,55 @@ def server_render_js(js_expression, options = {})
       render_options = ReactOnRails::ReactComponent::RenderOptions
                        .new(react_component_name: "generic-js", options: options)
 
-      js_code = <<-JS.strip_heredoc
-      (function() {
-        var htmlResult = '';
-        var consoleReplayScript = '';
-        var hasErrors = false;
-        var renderingError = null;
-        var renderingErrorObject = {};
-
-        try {
-          htmlResult =
-            (function() {
-              return #{js_expression};
-            })();
-        } catch(e) {
-          renderingError = e;
-          if (#{render_options.throw_js_errors}) {
-            throw e;
+      js_code = <<~JS
+        (function() {
+          var htmlResult = '';
+          var consoleReplayScript = '';
+          var hasErrors = false;
+          var renderingError = null;
+          var renderingErrorObject = {};
+
+          try {
+            htmlResult =
+              (function() {
+                return #{js_expression};
+              })();
+          } catch(e) {
+            renderingError = e;
+            if (#{render_options.throw_js_errors}) {
+              throw e;
+            }
+            htmlResult = ReactOnRails.handleError({e: e, name: null,
+              jsCode: '#{escape_javascript(js_expression)}', serverSide: true});
+            hasErrors = true;
+            var errorMessage = String(renderingError);
+            var errorStack = null;
+            // Guard against non-Error throws (e.g., throw null / throw "string").
+            // Boxed primitives (for example new Boolean(false)) are objects too.
+            if (renderingError && typeof renderingError === 'object') {
+              if ('message' in renderingError) {
+                errorMessage = String(renderingError.message);
+              }
+              if ('stack' in renderingError && renderingError.stack != null) {
+                errorStack = String(renderingError.stack);
+              }
+            }
+            renderingErrorObject = {
+              message: errorMessage,
+              stack: errorStack,
+            }
           }
-          htmlResult = ReactOnRails.handleError({e: e, name: null,
-            jsCode: '#{escape_javascript(js_expression)}', serverSide: true});
-          hasErrors = true;
-          renderingErrorObject = {
-            message: renderingError.message,
-            stack: renderingError.stack,
-          }
-        }
 
-        consoleReplayScript = ReactOnRails.getConsoleReplayScript();
+          consoleReplayScript = ReactOnRails.getConsoleReplayScript();
 
-        return JSON.stringify({
-            html: htmlResult,
-            consoleReplayScript: consoleReplayScript,
-            hasErrors: hasErrors,
-            renderingError: renderingErrorObject
-        });
+          return JSON.stringify({
+              html: htmlResult,
+              consoleReplayScript: consoleReplayScript,
+              hasErrors: hasErrors,
+              renderingError: renderingErrorObject
+          });
 
-      })()
+        })()
       JS
 
       result = ReactOnRails::ServerRenderingPool
@@ -767,11 +779,11 @@ def initialize_redux_stores(render_options)
       result << store_objects.each_with_object(declarations) do |redux_store_data, memo|
         store_name = redux_store_data[:store_name]
         props = props_string(redux_store_data[:props])
-        memo << <<-JS.strip_heredoc
-        reduxProps = #{props};
-        storeGenerator = ReactOnRails.getStoreGenerator(#{store_name.to_json});
-        store = storeGenerator(reduxProps, railsContext);
-        ReactOnRails.setStore(#{store_name.to_json}, store);
+        memo << <<~JS
+          reduxProps = #{props};
+          storeGenerator = ReactOnRails.getStoreGenerator(#{store_name.to_json});
+          store = storeGenerator(reduxProps, railsContext);
+          ReactOnRails.setStore(#{store_name.to_json}, store);
         JS
       end
       result

react_on_rails/lib/react_on_rails/locales/base.rb

@@ -181,13 +181,13 @@ def flatten(translations)
       end
 
       def template_translations
-        <<-JS.strip_heredoc
+        <<~JS
           export const translations = #{@translations};
         JS
       end
 
       def template_default
-        <<-JS.strip_heredoc
+        <<~JS
           import { defineMessages } from 'react-intl';
 
           const defaultLocale = '#{default_locale}';

react_on_rails/lib/react_on_rails/locales/to_js.rb

@@ -12,13 +12,13 @@ def file_format
       end
 
       def template_translations
-        <<-JS.strip_heredoc
+        <<~JS
           export const translations = #{@translations};
         JS
       end
 
       def template_default
-        <<-JS.strip_heredoc
+        <<~JS
           import { defineMessages } from 'react-intl';
 
           const defaultLocale = '#{default_locale}';

react_on_rails/lib/react_on_rails/packer_utils.rb

@@ -113,10 +113,10 @@ def self.packer_source_path_explicit?
     def self.check_manifest_not_cached
       return unless ::Shakapacker.config.cache_manifest?
 
-      msg = <<-MSG.strip_heredoc
-          ERROR: you have enabled cache_manifest in the #{Rails.env} env when using the
-          ReactOnRails::TestHelper.configure_rspec_to_compile_assets helper
-          To fix this: edit your config/shakapacker.yml file and set cache_manifest to false for test.
+      msg = <<~MSG
+        ERROR: you have enabled cache_manifest in the #{Rails.env} env when using the
+        ReactOnRails::TestHelper.configure_rspec_to_compile_assets helper
+        To fix this: edit your config/shakapacker.yml file and set cache_manifest to false for test.
       MSG
       puts wrap_message(msg)
       exit!

react_on_rails/lib/react_on_rails/pro_helper.rb

@@ -55,7 +55,7 @@ def generate_store_script(redux_store_data)
                                   script_options = nonce.present? ? { nonce: nonce } : {}
                                   immediate_script = content_tag(
                                     :script,
-                                    <<~JS.strip_heredoc.html_safe,
+                                    <<~JS.html_safe,
                                       typeof ReactOnRails === 'object' && ReactOnRails.reactOnRailsStoreLoaded('#{escaped_store_name}');
                                     JS
                                     script_options

react_on_rails/lib/react_on_rails/server_rendering_pool/ruby_embedded_java_script.rb

@@ -91,7 +91,7 @@ def trace_js_code_used(msg, js_code, file_name = "tmp/server-generated.js", forc
 
           # Set to anything to print generated code.
           File.write(file_name, js_code)
-          msg = <<-MSG.strip_heredoc
+          msg = <<~MSG
             #{'Z' * 80}
             [react_on_rails] #{msg}
             JavaScript code used: #{file_name}

react_on_rails/lib/react_on_rails/test_helper.rb

@@ -88,7 +88,7 @@ def self.ensure_assets_compiled(webpack_assets_status_checker: nil,
           @printed_once = true
 
           if ReactOnRails::Utils.using_packer_source_path_is_not_defined_and_custom_node_modules?
-            msg = <<-MSG.strip_heredoc
+            msg = <<~MSG
               WARNING: Define config/shakapacker.yml to include sourcePath to configure
               the location of your JavaScript source for React on Rails.
               Default location of #{source_path} is used.

react_on_rails/spec/dummy/spec/helpers/react_on_rails_helper_spec.rb

@@ -208,7 +208,7 @@ def helper.append_javascript_pack_tag(name, **options)
     let(:id) { "App-react-component-0" }
 
     let(:react_definition_script) do
-      <<-SCRIPT.strip_heredoc
+      <<~SCRIPT
         <script type="application/json" class="js-react-on-rails-component" \
         id="js-react-on-rails-component-App-react-component" \
         data-component-name="App" data-dom-id="App-react-component"
@@ -217,7 +217,7 @@ def helper.append_javascript_pack_tag(name, **options)
     end
 
     let(:react_definition_script_no_params) do
-      <<-SCRIPT.strip_heredoc
+      <<~SCRIPT
         <script type="application/json" class="js-react-on-rails-component" \
         id="js-react-on-rails-component-App-react-component" \
         data-component-name="App" data-dom-id="App-react-component"
@@ -331,7 +331,7 @@ def helper.append_javascript_pack_tag(name, **options)
       subject(:react_app) { react_component("App", props: props, random_dom_id: false) }
 
       let(:react_definition_script) do
-        <<-SCRIPT.strip_heredoc
+        <<~SCRIPT
           <script type="application/json" class="js-react-on-rails-component" \
           id="js-react-on-rails-component-App-react-component" \
           data-component-name="App" data-dom-id="App-react-component"
@@ -347,7 +347,7 @@ def helper.append_javascript_pack_tag(name, **options)
       subject(:react_app) { react_component("App", props: props, random_dom_id: true) }
 
       let(:react_definition_script) do
-        <<-SCRIPT.strip_heredoc
+        <<~SCRIPT
           <script type="application/json" class="js-react-on-rails-component" \
           id="js-react-on-rails-component-App-react-component-0" \
           data-component-name="App" data-dom-id="App-react-component-0"
@@ -369,7 +369,7 @@ def helper.append_javascript_pack_tag(name, **options)
       end
 
       let(:react_definition_script) do
-        <<-SCRIPT.strip_heredoc
+        <<~SCRIPT
           <script type="application/json" class="js-react-on-rails-component" \
           id="js-react-on-rails-component-App-react-component" \
           data-component-name="App" data-dom-id="App-react-component"
@@ -387,7 +387,7 @@ def helper.append_javascript_pack_tag(name, **options)
       let(:id) { "shaka_div" }
 
       let(:react_definition_script) do
-        <<-SCRIPT.strip_heredoc
+        <<~SCRIPT
           <script type="application/json" class="js-react-on-rails-component" \
           id="js-react-on-rails-component-shaka_div" \
           data-component-name="App" data-dom-id="shaka_div"
@@ -475,6 +475,89 @@ def helper.append_javascript_pack_tag(name, **options)
     end
   end
 
+  describe "#server_render_js error serialization" do
+    let(:runtime_available) do
+      ExecJS.runtime&.available?
+    rescue ExecJS::RuntimeUnavailable
+      false
+    end
+
+    let(:runtime_context) do
+      ExecJS.compile(<<~JS)
+        function runGeneratedCode(generatedCode) {
+          var ReactOnRails = {
+            handleError: function() { return ''; },
+            getConsoleReplayScript: function() { return ''; }
+          };
+          // Evaluate generated wrapper JS in a test sandbox before Ruby post-processing.
+          return eval(generatedCode);
+        }
+      JS
+    end
+
+    before do
+      skip "ExecJS runtime not available" unless runtime_available
+    end
+
+    it "generates JS with safe error property access for non-Error throws" do
+      captured_results = []
+
+      allow(ReactOnRails::ServerRenderingPool)
+        .to receive(:server_render_js_with_console_logging) do |js_code, _opts|
+          # Validate generated JS behavior directly before Ruby-side post-processing.
+          runtime_result = runtime_context.call("runGeneratedCode", js_code)
+          captured_results << JSON.parse(runtime_result)
+          {
+            "html" => "",
+            "consoleReplayScript" => "",
+            "hasErrors" => true,
+            "renderingError" => { "message" => "stub", "stack" => nil }
+          }
+        end
+
+      throw_cases = [
+        { expression: "(function() { throw null; })()", message: "null", stack: nil },
+        { expression: "(function() { throw { code: 42 }; })()", message: "[object Object]", stack: nil },
+        { expression: "(function() { throw new Error(\"boom\"); })()", message: "boom", stack: :present }
+      ]
+
+      throw_cases.each do |throw_case|
+        expect { server_render_js(throw_case[:expression]) }.not_to raise_error
+        captured_result = captured_results.last
+        expect(captured_result).to be_a(Hash)
+        expect(captured_result["hasErrors"]).to be(true)
+        expect(captured_result.dig("renderingError", "message")).to eq(throw_case[:message])
+
+        if throw_case[:stack] == :present
+          expect(captured_result.dig("renderingError", "stack")).to include("Error: boom")
+        else
+          expect(captured_result.dig("renderingError", "stack")).to be_nil
+        end
+      end
+
+      expect(captured_results.length).to eq(throw_cases.length)
+    end
+
+    it "raises PrerenderError when throw_js_errors is true and JS throws a non-Error value" do
+      allow(ReactOnRails::ServerRenderingPool)
+        .to receive(:server_render_js_with_console_logging) do |js_code, _opts|
+          runtime_context.call("runGeneratedCode", js_code)
+          # Defensive fallback: if runtime does not raise, force ProgramError path.
+          raise ExecJS::ProgramError, "Expected generated JS to throw"
+        rescue ExecJS::ProgramError
+          # Preserve original ProgramError; must precede the StandardError rescue.
+          raise
+        rescue StandardError => e
+          # Normalize non-ExecJS exceptions so server_render_js rescues consistently.
+          raise ExecJS::ProgramError, e.message
+        end
+
+      expect do
+        server_render_js("(function() { throw 42; })()", throw_js_errors: true)
+      end.to raise_error(ReactOnRails::PrerenderError)
+    end
+  end
+
   describe "#redux_store" do
     subject(:store) { redux_store("reduxStore", props: props, immediate_hydration: true) }