Components rendered in a subclass of AV::Base ignore the subclass

[p8]

When rendering a component in a subclass of ActionView::Base, methods called within the component are called on ActionView::Base instead of the subclass.
This prevents overriding methods on ActionView::Base in a subclass.

Steps to reproduce

# frozen_string_literal: true
#
require "bundler/inline"

gemfile(true) do
  source "https://rubygems.org"

  git_source(:github) { |repo| "https://github.com/#{repo}.git" }

  gem "rails", "~> 7.0.0"
  gem "view_component"
end

require "action_view/railtie"
require "action_view/testing/resolvers"

class CustomView < ActionView::Base
  def hi
    "Hi!"
  end
end

class GreetingComponent < ViewComponent::Base
  def call
    # Calling `hi` directly doesn't work because ViewComponent::Base doesn't
    # inherit from ActionView::Base:
    #
    #   hi # raises: undefined method `hi' for #<GreetingComponent....
    #
    helpers.hi
  end
end

view_paths = [ActionView::FixtureResolver.new(
  "main.erb" => %Q{
    <%= render GreetingComponent.new %>
  },
)]

custom_view = CustomView.with_empty_template_cache.with_view_paths view_paths
puts custom_view.render template: 'main'

Expected behavior

Methods called in components rendered in a subclass of ActionView::Base delegate methods to the subclass.

Actual behavior

Methods called in components rendered in a subclass of ActionView::Base delegate methods to the ActionView::Base.
Methods defined on the subclass need to be called on the helper.

[joelhawksley]

Thanks for filing! Might you be up for writing a test case for this? How do you think we should fix it?

[p8]

@joelhawksley Sorry for the late reply. I have no idea how to fix it. But I'll give it a try... 😄