Merge pull request #1707 from Shopify/vs/fix_engine_loading_older_rails

Fix engine loading for Rails < 7.2

Gemfile

@@ -55,3 +55,5 @@ group :test do
 end
 
 gem "kramdown", "~> 2.4"
+
+gem "prism", "< 0.16"

Gemfile.lock

@@ -255,6 +255,7 @@ GEM
       ast (~> 2.4.1)
       racc
     prettier_print (1.2.1)
+    prism (0.15.1)
     pry (0.14.2)
       coderay (~> 1.1)
       method_source (~> 1.0)
@@ -296,9 +297,9 @@ GEM
       zeitwerk (~> 2.5)
     rainbow (3.1.1)
     rake (13.0.6)
-    rbi (0.1.1)
+    rbi (0.1.3)
+      prism (>= 0.15.1, < 0.17)
       sorbet-runtime (>= 0.5.9204)
-      yarp (>= 0.11.0)
     redis (5.0.6)
       redis-client (>= 0.9.0)
     redis-client (0.17.0)
@@ -384,7 +385,6 @@ GEM
     yard-sorbet (0.8.1)
       sorbet-runtime (>= 0.5)
       yard (>= 0.9)
-    yarp (0.11.0)
     zeitwerk (2.6.11)
 
 PLATFORMS
@@ -412,6 +412,7 @@ DEPENDENCIES
   minitest-reporters
   net-smtp (= 0.4.0)
   nokogiri
+  prism (< 0.16)
   pry
   pry-byebug
   rails

lib/tapioca/loaders/loader.rb

@@ -80,8 +80,6 @@ def load_rails_application(environment_load: false, eager_load: false, app_root:
       def load_rails_engines
         return if engines.empty?
 
-        normalize_eager_load_paths_configuration!
-
         with_rails_application do
           run_initializers
 
@@ -112,7 +110,7 @@ def load_engines_in_zeitwerk_mode
         autoloader = Zeitwerk::Loader.new
 
         engines.each do |engine|
-          engine.config.all_eager_load_paths.each do |path|
+          eager_load_paths(engine).each do |path|
             # Zeitwerk only accepts existing directories in `push_dir`.
             next unless File.directory?(path)
             # We should not add directories that are already managed by a Zeitwerk loader.
@@ -133,7 +131,7 @@ def load_engines_in_classic_mode
         # We can't use `Rails::Engine#eager_load!` directly because it will raise as soon as it encounters
         # an error, which is not what we want. We want to try to load as much as we can.
         engines.each do |engine|
-          engine.config.all_eager_load_paths.each do |load_path|
+          eager_load_paths(engine).each do |load_path|
             Dir.glob("#{load_path}/**/*.rb").sort.each do |file|
               require_dependency file
             end
@@ -181,19 +179,6 @@ def engines
           .reject { |engine| gem_in_app_dir?(project_path, engine.config.root.to_path) }
       end
 
-      # Rails 7.2 renamed `eager_load_paths` to `all_eager_load_paths`, which maintains the same original functionality.
-      # The `eager_load_paths` method still exists, but doesn't return all paths anymore and causes Tapioca to miss some
-      # engine paths. The following commit is the change:
-      # https://github.com/rails/rails/commit/ebfca905db14020589c22e6937382e6f8f687664
-      #
-      # Here we make sure that the new `all_eager_load_paths` is always defined for every Rails version below 7.2, so
-      # that we can use it everywhere
-      def normalize_eager_load_paths_configuration!
-        return if Rails::VERSION::MAJOR >= 7 && Rails::VERSION::MINOR >= 2
-
-        engines.each { |e| e.config.all_eager_load_paths = e.config.eager_load_paths }
-      end
-
       sig { params(path: String).void }
       def safe_require(path)
         require path
@@ -239,6 +224,17 @@ def require_helper(file)
 
         require(file)
       end
+
+      # Rails 7.2 renamed `eager_load_paths` to `all_eager_load_paths`, which maintains the same original functionality.
+      # The `eager_load_paths` method still exists, but doesn't return all paths anymore and causes Tapioca to miss some
+      # engine paths. The following commit is the change:
+      # https://github.com/rails/rails/commit/ebfca905db14020589c22e6937382e6f8f687664
+      sig { params(engine: T.class_of(Rails::Engine)).returns(T::Array[String]) }
+      def eager_load_paths(engine)
+        config = engine.config
+
+        (config.respond_to?(:all_eager_load_paths) && config.all_eager_load_paths) || config.eager_load_paths
+      end
     end
   end
 end

lib/tapioca/static/symbol_loader.rb

@@ -27,7 +27,15 @@ def engine_symbols(gem)
 
           return Set.new unless gem_engine
 
-          paths = gem_engine.config.all_eager_load_paths.flat_map do |load_path|
+          # https://github.com/rails/rails/commit/ebfca905db14020589c22e6937382e6f8f687664
+          config = gem_engine.config
+          eager_load_paths = if config.respond_to?(:all_eager_load_paths)
+            config.all_eager_load_paths
+          else
+            config.eager_load_paths
+          end
+
+          paths = eager_load_paths.flat_map do |load_path|
             Pathname.glob("#{load_path}/**/*.rb")
           end