Direct people to refresh OIDC connection

Not the best UX but the easiest next step to implement. Next we should:

* Include link in error message instead of redirecting straight there.
  Otherwise users may feel disoriented.
* Provide a custom error message?

app/controllers/admin/dfc_product_imports_controller.rb

@@ -32,6 +32,9 @@ module Admin
            ActionController::ParameterMissing => e
       flash[:error] = e.message
       redirect_to admin_product_import_path
+    rescue Rack::OAuth2::Client::Error
+      flash[:error] = t(".connection_invalid")
+      redirect_to admin_oidc_settings_path
     end
 
     def import

config/locales/en.yml

@@ -847,6 +847,9 @@ en:
         map: Map
 
     dfc_product_imports:
+      connection_invalid: |
+        Connecting with your OIDC account failed.
+        Please refresh your OIDC connection.
       index:
         title: "DFC product catalog"
         catalog_url: "%{count} products to be imported from: %{catalog_url}"

spec/system/admin/dfc_product_import_spec.rb

@@ -114,4 +114,25 @@ RSpec.describe "DFC Product Import" do
     click_button "Preview"
     expect(page).to have_content "param is missing or the value is empty: catalog_url"
   end
+
+  it "prompts to refresh OIDC connection", vcr: true do
+    # Stale access token will be renewed, but refresh token isn't valid either.
+    user.oidc_account.update!(
+      refresh_token: "something-expired-or-invalid",
+      updated_at: 1.day.ago,
+    )
+
+    catalog_url = "https://example.net/unauthorized"
+    stub_request(:get, catalog_url).to_return(status: [401, "Unauthorized"])
+
+    visit admin_product_import_path
+
+    select enterprise.name, from: "Enterprise"
+    fill_in "catalog_url", with: catalog_url
+
+    click_button "Preview"
+
+    expect(page).to have_content "OIDC Settings"
+    expect(page).to have_content "Connecting with your OIDC account failed."
+  end
 end