DEV: Attempt to fix flaky signup spec (#29396)

spec/system/page_objects/modals/base.rb

@@ -5,6 +5,7 @@ module PageObjects
     class Base
       include Capybara::DSL
       include RSpec::Matchers
+      include SystemHelpers
 
       BODY_SELECTOR = ""
 

spec/system/page_objects/modals/signup.rb

@@ -31,8 +31,13 @@ module PageObjects
         click("#login-link")
       end
 
-      def click_create_account
-        click(".modal.create-account .btn-primary")
+      def click_create_account(expect_success: true)
+        try_until_success(timeout: 5) do
+          click(".modal.create-account .btn-primary")
+          if expect_success
+            expect(page).to have_css(".modal.create-account .btn-primary.is-loading")
+          end
+        end
       end
 
       def has_password_input?

spec/system/page_objects/pages/signup.rb

@@ -31,8 +31,11 @@ module PageObjects
         click("#login-link")
       end
 
-      def click_create_account
-        click(".signup-fullpage .btn-primary")
+      def click_create_account(expect_success: true)
+        try_until_success(timeout: 5) do
+          click(".signup-fullpage .btn-primary")
+          expect(page).to have_css(".signup-fullpage .btn-primary.is-loading") if expect_success
+        end
       end
 
       def has_password_input?

spec/system/signup_spec.rb

@@ -131,7 +131,7 @@ shared_examples "signup scenarios" do |signup_page_object, login_page_object|
           .fill_email("johndoe@example.com")
           .fill_username("john")
           .fill_password("supersecurepassword")
-          .click_create_account
+          .click_create_account(expect_success: false)
         expect(signup_form).to have_content(I18n.t("js.user_fields.required", name: "Occupation"))
         expect(signup_form).to have_no_css(".account-created")
       end