Raise when options_for_select is used as a value

lib/phlex/rails.rb

@@ -22,6 +22,8 @@ class HelpersCalledBeforeRenderError < StandardError; end
 		autoload :Streaming, "phlex/rails/streaming"
 
 		autoload :Builder, "phlex/rails/builder"
+
+		autoload :Never, "phlex/rails/never"
 	end
 
 	CSV.prepend(Phlex::Rails::CSV)

lib/phlex/rails/helpers/options_for_select.rb

@@ -4,5 +4,17 @@ module Phlex::Rails::Helpers::OptionsForSelect
 	extend Phlex::Rails::HelperMacros
 
 	# [Rails Docs](https://api.rubyonrails.org/classes/ActionView/Helpers/FormOptionsHelper.html#method-i-options_for_select)
-	register_output_helper def options_for_select(...) = nil
+	def options_for_select(*args, **kwargs, &block)
+		output = if block
+			view_context.options_for_select(*args, **kwargs) { |*args| capture(*args, &block) }
+		else
+			view_context.options_for_select(*args, **kwargs)
+		end
+
+		raw(output)
+
+		Phlex::Rails::Never.new do
+			raise Phlex::ArgumentError.new("You can’t use options_for_select as an argument for a select helper in Phlex. Instead, pass a block and call options_for_select inside that block.")
+		end
+	end
 end

lib/phlex/rails/helpers/select_tag.rb

@@ -4,5 +4,15 @@ module Phlex::Rails::Helpers::SelectTag
 	extend Phlex::Rails::HelperMacros
 
 	# [Rails Docs](https://api.rubyonrails.org/classes/ActionView/Helpers/FormTagHelper.html#method-i-select_tag)
-	register_output_helper def select_tag(...) = nil
+	# register_output_helper def select_tag(...) = nil
+
+	def select_tag(name, *, **, &block)
+		output = if block
+			view_context.select_tag(name, capture(&block), *, **)
+		else
+			view_context.select_tag(name, *, **)
+		end
+
+		raw(output)
+	end
 end

lib/phlex/rails/never.rb

@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+class Phlex::Rails::Never < BasicObject
+	def initialize(&block)
+		@block = block
+	end
+
+	def method_missing(method_name, *, **)
+		@block.call(method_name, *, **)
+	end
+end

test/helpers/options_for_select.test.rb

@@ -0,0 +1,91 @@
+# frozen_string_literal: true
+
+test "options_for_select as a value for a select_tag" do
+	component = Class.new(Phlex::HTML) do
+		include Phlex::Rails::Helpers::SelectTag
+		include Phlex::Rails::Helpers::OptionsForSelect
+
+		define_method :view_template do
+			select_tag :test, options_for_select([["Option 1", 1], ["Option 2", 2]])
+		end
+	end
+
+	error = assert_raises Phlex::ArgumentError do
+		render(component)
+	end
+
+	assert error.message.include?("options_for_select")
+end
+
+test "options_for_select as a value for a form_with select" do
+	component = Class.new(Phlex::HTML) do
+		include Phlex::Rails::Helpers::FormWith
+		include Phlex::Rails::Helpers::OptionsForSelect
+
+		define_method :view_template do
+			form_with(url: "/") do |form|
+				form.select(:test, options_for_select([["Option 1", 1], ["Option 2", 2]]))
+			end
+		end
+	end
+
+	controller.define_singleton_method(:form_authenticity_token) { |_| "(example form authenticity token)" }
+
+	error = assert_raises Phlex::ArgumentError do
+		render(component)
+	end
+
+	assert error.message.include?("options_for_select")
+end
+
+test "options_for_select in a form with select" do
+	component = Class.new(Phlex::HTML) do
+		include Phlex::Rails::Helpers::FormWith
+		include Phlex::Rails::Helpers::OptionsForSelect
+
+		define_method :view_template do
+			form_with(url: "/") do |form|
+				form.select(:test) do
+					options_for_select([["Option 1", 1], ["Option 2", 2]])
+				end
+			end
+		end
+	end
+
+	controller.define_singleton_method(:form_authenticity_token) { |_| "(example form authenticity token)" }
+
+	output = render(component)
+
+	assert_equivalent_html output, <<~HTML
+		<form action="/" accept-charset="UTF-8" method="post">
+			<input name="utf8" type="hidden" value="✓" autocomplete="off">
+			<input type="hidden" name="authenticity_token" value="(example form authenticity token)" autocomplete="off">
+			<select name="test">
+				<option value="1">Option 1</option>
+				<option value="2">Option 2</option>
+			</select>
+		</form>
+	HTML
+end
+
+test "options_for_select in a select_tag" do
+	component = Class.new(Phlex::HTML) do
+		include Phlex::Rails::Helpers::SelectTag
+		include Phlex::Rails::Helpers::OptionsForSelect
+
+		define_method :view_template do
+			select_tag :test do
+				options_for_select([["Option 1", 1], ["Option 2", 2]])
+			end
+		end
+	end
+
+	output = render(component)
+
+	assert_equivalent_html output, <<~HTML
+		<select name="test" id="test">
+			<option value="1">Option 1</option>
+			<option value="2">Option 2</option>
+		</select>
+	HTML
+end