Normalize error message among importers

A similar validation is done in Fogbugz and Gitea importers but the
error message wasn't the same. This commit normalizes the error message
to be the same in both importers.

app/controllers/import/gitea_controller.rb

@@ -3,6 +3,8 @@
 class Import::GiteaController < Import::GithubController
   extend ::Gitlab::Utils::Override
 
+  before_action :verify_blocked_uri, only: :status
+
   def new
     if session[access_token_key].present? && provider_url.present?
       redirect_to status_import_url
@@ -16,13 +18,7 @@ class Import::GiteaController < Import::GithubController
 
   # Must be defined or it will 404
   def status
-    if blocked_url?
-      session[access_token_key] = nil
-
-      redirect_to new_import_url, alert: _('Specified URL cannot be used.')
-    else
-      super
-    end
+    super
   end
 
   private
@@ -61,8 +57,8 @@ class Import::GiteaController < Import::GithubController
     { host: provider_url, api_version: 'v1' }
   end
 
-  def blocked_url?
-    Gitlab::UrlBlocker.blocked_url?(
+  def verify_blocked_uri
+    Gitlab::UrlBlocker.validate!(
       provider_url,
       {
         allow_localhost: allow_local_requests?,
@@ -70,6 +66,10 @@ class Import::GiteaController < Import::GithubController
         schemes: %w(http https)
       }
     )
+  rescue Gitlab::UrlBlocker::BlockedUrlError => e
+    session[access_token_key] = nil
+
+    redirect_to new_import_url, alert: _('Specified URL cannot be used: "%{reason}"') % { reason: e.message }
   end
 
   def allow_local_requests?

changelogs/unreleased/normalize-import-error-messages.yml

+---
+title: Normalize error message between Gitea and Fogbugz importers
+merge_request: 28802
+author:
+type: other

locale/gitlab.pot

@@ -19025,9 +19025,6 @@ msgstr ""
 msgid "Specific Runners"
 msgstr ""
 
-msgid "Specified URL cannot be used."
-msgstr ""
-
 msgid "Specified URL cannot be used: \"%{reason}\""
 msgstr ""
 

spec/controllers/import/gitea_controller_spec.rb

@@ -42,7 +42,7 @@ describe Import::GiteaController do
             get :status, format: :json
 
             expect(controller).to redirect_to(new_import_url)
-            expect(flash[:alert]).to eq('Specified URL cannot be used.')
+            expect(flash[:alert]).to eq('Specified URL cannot be used: "Only allowed schemes are http, https"')
           end
         end
       end