Sage Child/Parent Theme Support

Start with the linked parent/child theme discussion, then review the setup points named in helpers.php, composer.php, resources/views/, style.css, View Composers, and Roots config(). Clarify whether the goal is implementation support or a setup guide, and define done as documented or working parent inheritance for views, composers, helpers, and configuration.

• I've read the guidelines for Contributing to Roots Projects
• This request isn't a duplicate of an existing issue
• I've read the docs and followed them (if applicable)
• This is not a personal support request that should be posted on the Roots Discourse community

Description

Related to this discussion: https://discourse.roots.io/t/sage-10-as-parent-child-themes/
It would be fantastic to get some feedback ftom @Log1x and @QWp6t

Steps to reproduce

1. Parent Theme:

1.1 Make a new Sage 10 Theme with custom Namespace "Parent" in folder 'parent'
1.2 Add some View Composers variables such as "siteName" and reference it in a blade file
1.3 Add a function my_test_function() to helpers.php
1.4 Activate the theme, it should be working and the variable $siteName is outputted correctly

2. Child Theme

1.1 Make a new Sage 10 Theme and leave the Namespace as "App" in folder child
1.2 Add Template: parent to style.css
1.3 Remove all blade files from ./resources/views/
1.4 Use \Parent\my_test_function() e.g. in a child View Composer
1.5 Autoload parent theme Class in composer.php:

"psr-4": {
      "App\\": "app/",
      "Parent\\": "./../parent/app/"
    }

1.5 Activate the child theme

Expected behavior: [What you expect to happen]

• Blade views are loaded from parent theme
• View Composers are loaded from parent theme as well as from child theme (ideally overwriting parent values)
• Functions from parent theme in helpers.php are available via \Parent\my_test_function()
• Config via \Roots\config() is loading parent theme value, if child theme value is not set

Actual behavior: [What actually happens]

• Blade views are loaded from parent theme
• Undefined variable: siteName errors, the View Composers from the parent theme are missing
• Call to undefined function errors when calling \Parent\my_test_function()
• Error if e.g. \Roots\config('app.debug') is not set in child theme as function not checks against parent value

Reproduces how often: [What percentage of the time does it reproduce?]

In the current setup 100%. More tests required.

Versions

Sage 10.0.0-alpha

Additional information

It would be fantastic to get a very short summary how child/parent themes should be set-up with Sage 10.