Loader: refactor loader tests to avoid code duplication
Most of the loaders are tested but are reusing some duplicated code. Improve and remove such duplication.
Migrated from T1238 (view on Phabricator)
Staging instance, all changes can be removed at any time
Most of the loaders are tested but are reusing some duplicated code. Improve and remove such duplication.
Migrated from T1238 (view on Phabricator)