Fix ActionView::MissingTemplate for static controller

[skryukov]

There are two ways to address the ActionView::MissingTemplate issue: using a respond_to block or forcing the :html format. I went with the latter since it prevents all cryptic messages and makes the controller always render an Inertia response.

Fixes #248

[richardboehme]

Can confirm this works in our app. The server now always responds with HTML, no matter the requested content type.

[bknoles]

I played with this a bit today. I'm in favor of wrapping the renderer in a repond_to block.

IMO the issue is that we're raising a confusing exception.

With a respond_to block constraining us to html formats, Rails raises an UnknownFormat error, which I think is a helpful exception. Since there are still ways the app can decide to support /some_inertia_path.some_other_format if it wants to, coercing it in the renderer is overly prescriptive for me. What do you think?

[bknoles]

We could also constrain the format coercion to the static controller, perhaps... this seems to work if I forward the formats argument on to the render method call in the renderer:

module InertiaRails
  class StaticController < InertiaRails.configuration.parent_controller.constantize
    def static
      render inertia: params[:component], formats: [:html]
    end
  end
end