```ruby
module FrontEndBuilds
  class Engine < ::Rails::Engine
    isolate_namespace FrontEndBuilds

    config.generators do |g|
      g.test_framework :rspec, fixture: false
      g.fixture_replacement :factory_girl, dir: 'spec/factories'
      g.assets false
      g.helper false
    end

     # Initializer to combine this engines static assets with the static assets of the hosting site.
    initializer "static assets" do |app|
      app.middleware.insert_before(::ActionDispatch::Static, ::ActionDispatch::Static, "#{root}/public")
    end

    initializer "front_end_assets.assets.precompile" do |app|
      app.config.assets.precompile += %w(
        front_end_builds/vendor.css
        front_end_builds/admin.css
        front_end_builds/vendor.js
        front_end_builds/admin.js
        front_end_builds/fontawesome-webfont.woff
      )
      app.config.assets.precompile << /\.(?:svg|eot|woff|ttf)$/
    end
  end
end
```

Use `group: all` so initializer is triggered during asset comp.
user
```ruby
module FrontEndBuilds
  class Engine < ::Rails::Engine
    isolate_namespace FrontEndBuilds

    config.generators do |g|
      g.test_framework :rspec, fixture: false
      g.fixture_replacement :factory_girl, dir: 'spec/factories'
      g.assets false
      g.helper false
    end

     # Initializer to combine this engines static assets with the static assets of the hosting site.
    initializer "static assets" do |app|
      app.middleware.insert_before(::ActionDispatch::Static, ::ActionDispatch::Static, "#{root}/public")
    end

    initializer "front_end_assets.assets.precompile", group: :all do |app|
      app.config.assets.precompile += %w(
        front_end_builds/vendor.css
        front_end_builds/admin.css
        front_end_builds/vendor.js
        front_end_builds/admin.js
      )
    end
  end
end
```
assistant