raise if helpers called from #initialize

lib/phlex/rails/sgml.rb

@@ -10,7 +10,11 @@ def render_in(...)
 			end
 
 			module Overrides
+				class HelpersCalledBeforeRenderError < StandardError; end
+
 				def helpers
+					raise HelpersCalledBeforeRenderError.new("Do not use rails helpers until after the view has been rendered.") unless @_view_context
+
 					if defined?(ViewComponent::Base) && ViewComponent::Base === @_view_context
 						@_view_context.helpers
 					else
@@ -22,22 +26,22 @@ def render(*args, **kwargs, &block)
 					renderable = args[0]
 
 					case renderable
-					when Phlex::SGML, Proc, Method, String
-						return super
-					when Class
-						return super if renderable < Phlex::SGML
-					when Enumerable
-						return super unless ActiveRecord::Relation === renderable
-					when nil
-						partial = kwargs.delete(:partial)
+						when Phlex::SGML, Proc, Method, String
+							return super
+						when Class
+							return super if renderable < Phlex::SGML
+						when Enumerable
+							return super unless ActiveRecord::Relation === renderable
+						when nil
+							partial = kwargs.delete(:partial)
 
-						if partial # this is a hack to get around https://github.com/rails/rails/issues/51015
-							return raw(
-								@_view_context.render(partial, **kwargs) do |*yielded_args|
-									capture(*yielded_args, &block)
-								end,
-							)
-						end
+							if partial # this is a hack to get around https://github.com/rails/rails/issues/51015
+								return raw(
+									@_view_context.render(partial, **kwargs) do |*yielded_args|
+										capture(*yielded_args, &block)
+									end,
+								)
+							end
 					end
 
 					output = if block

test/dummy/app/controllers/helpers_controller.rb

@@ -3,6 +3,10 @@
 class HelpersController < ApplicationController
 	layout false
 
+	def helper_in_initializer
+		render Helpers::HelperInInitializer.new
+	end
+
 	def form_with
 		render Helpers::FormWithView.new
 	end

test/dummy/app/views/helpers/helper_in_initializer.rb

@@ -0,0 +1,9 @@
+# frozen_string_literal: true
+
+class Helpers::HelperInInitializer < ApplicationView
+	include Phlex::Rails::Helpers::Routes
+
+	def initialize
+		helpers_helper_in_initializer_path
+	end
+end

test/dummy/config/routes.rb

@@ -13,6 +13,7 @@
 	get "/layout/with_erb_view", to: "layout#with_erb_view"
 	get "/layout/with_phlex_view", to: "layout#with_phlex_view"
 
+	get "/helpers/helper_in_initializer", to: "helpers#helper_in_initializer"
 	get "/helpers/form_with", to: "helpers#form_with"
 	get "/helpers/tag", to: "helpers#tag"
 	get "/helpers/missing_helper", to: "helpers#missing_helper"

test/phlex/helpers_test.rb

@@ -14,6 +14,14 @@ class HelpersTest < ActionDispatch::IntegrationTest
 		end
 	end
 
+	test "helper in initializer" do
+		error = assert_raises(Phlex::Rails::SGML::Overrides::HelpersCalledBeforeRenderError) do
+			get "/helpers/helper_in_initializer"
+		end
+
+		assert_equal "Do not use rails helpers until after the view has been rendered.", error.message
+	end
+
 	test "form with" do
 		get "/helpers/form_with"