Add a TestContext as a future replacement to the FakeContext

gems/gitlab-backup-cli/spec/support/helpers.rb

@@ -32,6 +32,10 @@ def build_fake_context
       env: ActiveSupport::EnvironmentInquirer.new('test')
     )
   end
+
+  def build_test_context
+    TestContext.new
+  end
 end
 
 RSpec.configure do |config|

gems/gitlab-backup-cli/spec/support/test_context.rb

+# frozen_string_literal: true
+
+class TestContext < Gitlab::Backup::Cli::Context::SourceContext
+  def gitlab_basepath
+    test_helpers.spec_path.join('../../..')
+  end
+
+  def backup_basedir
+    test_helpers.temp_path.join('backups')
+  end
+
+  private
+
+  def test_helpers
+    Class.new.extend(GitlabBackupHelpers)
+  end
+end