Allow custom OAuth URLs

app/controllers/shopify_app/sessions_controller.rb

@@ -46,7 +46,7 @@ def authenticate
     def start_oauth
       auth_attributes = ShopifyAPI::Auth::Oauth.begin_auth(
         shop: sanitized_shop_name,
-        redirect_path: "/auth/shopify/callback",
+        redirect_path: ShopifyApp.configuration.login_callback_url,
         is_online: user_session_expected?
       )
       cookies.encrypted[auth_attributes[:cookie].name] = {

config/routes.rb

@@ -1,14 +1,17 @@
 # frozen_string_literal: true
 
 ShopifyApp::Engine.routes.draw do
+  login_url = ShopifyApp.configuration.login_url.gsub(/^#{ShopifyApp.configuration.root_url}/, "")
+  login_callback_url = ShopifyApp.configuration.login_callback_url.gsub(/^#{ShopifyApp.configuration.root_url}/, "")
+
   controller :sessions do
-    get "login" => :new, :as => :login
-    post "login" => :create, :as => :authenticate
+    get login_url => :new, :as => :login
+    post login_url => :create, :as => :authenticate
     get "logout" => :destroy, :as => :logout
   end
 
   controller :callback do
-    get "auth/shopify/callback" => :callback
+    get login_callback_url => :callback
   end
 
   namespace :webhooks do

lib/shopify_app/configuration.rb

@@ -24,6 +24,7 @@ class Configuration
     # customise urls
     attr_accessor :root_url
     attr_writer :login_url
+    attr_writer :login_callback_url
 
     # customise ActiveJob queue names
     attr_accessor :scripttags_manager_queue_name
@@ -50,6 +51,10 @@ def login_url
       @login_url || File.join(@root_url, "login")
     end
 
+    def login_callback_url
+      @login_callback_url || File.join(@root_url, "auth/shopify/callback")
+    end
+
     def user_session_repository=(klass)
       ShopifyApp::SessionRepository.user_storage = klass
     end

test/routes/callback_routes_test.rb

@@ -9,7 +9,33 @@ class CallbackRoutesTest < ActionController::TestCase
     ShopifyApp.configuration = nil
   end
 
+  teardown do
+    ShopifyApp.configuration = nil
+  end
+
   test "auth_shopify_callback routes to callback#callback" do
     assert_routing "/auth/shopify/callback", controller: "shopify_app/callback", action: "callback"
   end
+
+  test "callback route doesn't change with custom root URL because it is in an engine" do
+    ShopifyApp.configuration.root_url = "/new-root"
+    Rails.application.reload_routes!
+
+    assert_routing "/auth/shopify/callback", controller: "shopify_app/callback", action: "callback"
+  end
+
+  test "callback route changes with custom callback URL" do
+    ShopifyApp.configuration.login_callback_url = "/other-callback"
+    Rails.application.reload_routes!
+
+    assert_routing "/other-callback", controller: "shopify_app/callback", action: "callback"
+  end
+
+  test "callback route strips out root URL if both are set since it runs in an engine" do
+    ShopifyApp.configuration.root_url = "/new-root"
+    ShopifyApp.configuration.login_callback_url = "/new-root/other-callback"
+    Rails.application.reload_routes!
+
+    assert_routing "/other-callback", controller: "shopify_app/callback", action: "callback"
+  end
 end

test/routes/sessions_routes_test.rb

@@ -9,6 +9,10 @@ class SessionsRoutesTest < ActionController::TestCase
     ShopifyApp.configuration = nil
   end
 
+  teardown do
+    ShopifyApp.configuration = nil
+  end
+
   test "login routes to sessions#new" do
     assert_routing "/login", { controller: "shopify_app/sessions", action: "new" }
   end
@@ -20,4 +24,29 @@ class SessionsRoutesTest < ActionController::TestCase
   test "logout routes to sessions#destroy" do
     assert_routing "/logout", { controller: "shopify_app/sessions", action: "destroy" }
   end
+
+  test "login route doesn't change with custom root URL because it is in an engine" do
+    ShopifyApp.configuration.root_url = "/new-root"
+    Rails.application.reload_routes!
+
+    assert_routing "/login", { controller: "shopify_app/sessions", action: "new" }
+    assert_routing({ method: "post", path: "/login" }, { controller: "shopify_app/sessions", action: "create" })
+  end
+
+  test "login route changes with custom login URL" do
+    ShopifyApp.configuration.login_url = "/other-login"
+    Rails.application.reload_routes!
+
+    assert_routing "/other-login", { controller: "shopify_app/sessions", action: "new" }
+    assert_routing({ method: "post", path: "/other-login" }, { controller: "shopify_app/sessions", action: "create" })
+  end
+
+  test "login route strips out root URL if both are set since it runs in an engine" do
+    ShopifyApp.configuration.root_url = "/new-root"
+    ShopifyApp.configuration.login_url = "/new-root/other-login"
+    Rails.application.reload_routes!
+
+    assert_routing "/other-login", { controller: "shopify_app/sessions", action: "new" }
+    assert_routing({ method: "post", path: "/other-login" }, { controller: "shopify_app/sessions", action: "create" })
+  end
 end