Fix GitHub project's link on import page when provider has a custom URL

CHANGELOG

@@ -97,6 +97,7 @@ v 8.7.0 (unreleased)
   - Fix emoji catgories in the emoji picker
   - Execute system web hooks on push to the project
   - Allow enable/disable push events for system hooks
+  - Fix GitHub project's link in the import page when provider has a custom URL
 
 v 8.6.7 (unreleased)
   - Fix vulnerability that made it possible to enumerate private projects belonging to group

app/helpers/import_helper.rb

+module ImportHelper
+  def github_project_link(path_with_namespace)
+    link_to path_with_namespace, github_project_url(path_with_namespace), target: '_blank'
+  end
+
+  private
+
+  def github_project_url(path_with_namespace)
+    "#{github_root_url}/#{path_with_namespace}"
+  end
+
+  def github_root_url
+    return @github_url if defined?(@github_url)
+
+    provider = Gitlab.config.omniauth.providers.find { |p| p.name == 'github' }
+    @github_url = provider.fetch('url', 'https://github.com') if provider
+  end
+end

app/views/import/github/status.html.haml

@@ -26,7 +26,7 @@
       - @already_added_projects.each do |project|
         %tr{id: "project_#{project.id}", class: "#{project_status_css_class(project.import_status)}"}
           %td
-            = link_to project.import_source, "https://github.com/#{project.import_source}", target: "_blank"
+            = github_project_link(project.import_source)
           %td
             = link_to project.path_with_namespace, [project.namespace.becomes(Namespace), project]
           %td.job-status
@@ -43,7 +43,7 @@
       - @repos.each do |repo|
         %tr{id: "repo_#{repo.id}"}
           %td
-            = link_to repo.full_name, "https://github.com/#{repo.full_name}", target: "_blank"
+            = github_project_link(repo.full_name)
           %td.import-target
             = repo.full_name
           %td.import-actions.job-status

spec/helpers/import_helper_spec.rb

+require 'rails_helper'
+
+describe ImportHelper do
+  describe '#github_project_link' do
+    context 'when provider does not specify a custom URL' do
+      it 'uses default GitHub URL' do
+        allow(Gitlab.config.omniauth).to receive(:providers).
+          and_return([Settingslogic.new('name' => 'github')])
+
+        expect(helper.github_project_link('octocat/Hello-World')).
+          to include('href="https://github.com/octocat/Hello-World"')
+      end
+    end
+
+    context 'when provider specify a custom URL' do
+      it 'uses custom URL' do
+        allow(Gitlab.config.omniauth).to receive(:providers).
+          and_return([Settingslogic.new('name' => 'github', 'url' => 'https://github.company.com')])
+
+        expect(helper.github_project_link('octocat/Hello-World')).
+          to include('href="https://github.company.com/octocat/Hello-World"')
+      end
+    end
+  end
+end