Allow to choose a custom routes' mount point during install

Since we moved the frontend as an injectable templating system,
there are some manual steps to do to make the application work
when a user wants to change the mount point of where Solidus is
installed.

With this change, along with solidusio/solidus_starter_frontend#359,
we allow the user to select the mount point during the install, and
all the changes required are handled by the install script.

admin/lib/generators/solidus_admin/install/install_generator.rb

@@ -9,7 +9,7 @@ class InstallGenerator < Rails::Generators::Base
 
  def install_solidus_core_support
  route <<~RUBY
- mount SolidusAdmin::Engine, at: '/admin', constraints: ->(req) {
+ mount SolidusAdmin::Engine, at: '#{solidus_mount_point}admin', constraints: ->(req) {
  req.cookies['solidus_admin'] != 'false' &&
  req.params['solidus_admin'] != 'false'
  }
@@ -37,7 +37,15 @@ def install_lookbook
  gem "actioncable"
  end
 
- route "mount Lookbook::Engine, at: '/lookbook' if Rails.env.development?"
+ route "mount Lookbook::Engine, at: '#{solidus_mount_point}lookbook' if Rails.env.development?"
+ end
+
+ private
+
+ def solidus_mount_point
+ mount_point = Spree::Core::Engine.routes.find_script_name({})
+ mount_point += "/" unless mount_point.end_with?("/")
+ mount_point
  end
  end
  end

core/lib/generators/solidus/install/install_generator.rb

@@ -39,6 +39,7 @@ class InstallGenerator < Rails::Generators::AppBase
  class_option :user_class, type: :string
  class_option :admin_email, type: :string
  class_option :admin_password, type: :string
+ class_option :mount_point, type: :string, desc: "Indicates where Solidus should be mounted. Defaults to '/'"
 
  class_option :frontend, type: :string, enum: FRONTENDS.map { _1[:name] }, default: nil, desc: "Indicates which frontend to install."
  class_option :authentication, type: :string, enum: AUTHENTICATIONS.map { _1[:name] }, default: nil, desc: "Indicates which authentication system to install."
@@ -87,6 +88,36 @@ def prepare_options
  ENV['SOLIDUS_SKIP_MIGRATIONS_CHECK'] = 'true'
  end
 
+ def install_routes
+ if Pathname(app_path).join('config', 'routes.rb').read.include? CORE_MOUNT_ROUTE
+ say_status :route_exist, CORE_MOUNT_ROUTE, :blue
+ else
+ say_status :installing, "solidus routes"
+ mount_point = options[:mount_point] || ask_with_default(
+ desc: 'Where would you like to mount Solidus? (E.g. "/store" or "/shop")',
+ default: '/',
+ )
+
+ shell.mute do
+ route <<~RUBY
+ # This line mounts Solidus's routes at the root of your application.
+ #
+ # Unless you manually picked only a subset of Solidus components, this will mount routes for:
+ # - solidus_backend
+ # - solidus_api
+ # This means, any requests to URLs such as /admin/products, will go to Spree::Admin::ProductsController.
+ #
+ # If you are using the Starter Frontend as your frontend, be aware that all the storefront routes are defined
+ # separately in this file and are not part of the Solidus::Core::Engine engine.
+ #
+ # If you would like to change where this engine is mounted, simply change the :at option to something different.
+ # We ask that you don't use the :as option here, as Solidus relies on it being the default of "spree"
+ #{CORE_MOUNT_ROUTE}, at: '#{mount_point}'
+ RUBY
+ end
+ end
+ end
+
  def add_files
  template 'config/initializers/spree.rb.tt', 'config/initializers/spree.rb'
  end
@@ -134,21 +165,6 @@ def create_database
  rake 'db:create'
  end
 
- def install_routes
- if Pathname(app_path).join('config', 'routes.rb').read.include? CORE_MOUNT_ROUTE
- say_status :route_exist, CORE_MOUNT_ROUTE, :blue
- else
- route <<~RUBY
- # This line mounts Solidus's routes at the root of your application.
- # This means, any requests to URLs such as /products, will go to Spree::ProductsController.
- # If you would like to change where this engine is mounted, simply change the :at option to something different.
- #
- # We ask that you don't use the :as option here, as Solidus relies on it being the default of "spree"
- #{CORE_MOUNT_ROUTE}, at: '/'
- RUBY
- end
- end
-
  def run_migrations
  if @run_migrations
  say_status :running, "migrations"
@@ -209,6 +225,27 @@ def bundle_command(command, env = {})
  Bundler.reset_paths!
  end
 
+ def ask_with_default(desc:, default:)
+ if options[:auto_accept]
+ say_status :using, "#{default} (default)"
+ return default
+ end
+
+ default_label = " (#{set_color :default, :bold}: \"#{default}\")" if default
+
+ say_status :question, "#{desc}#{default_label}.", :yellow
+ answer = ask(set_color("answer:".rjust(13), :blue, :bold)).to_s.downcase.presence
+
+ case answer
+ when nil
+ say_status :using, "#{default} (default)"
+ default
+ else
+ say_status :using, answer
+ answer
+ end
+ end
+
  def ask_with_description(desc:, limited_to:, default:)
  loop do
  say_status :question, desc, :yellow