So, you want to help test Migrate in Core? Excellent. We're currently focusing our efforts on ensuring that Drupal 6 sites (core configuration, content, and standard CCK fields) can be migrated cleanly into Drupal 8 via the Migrate Drupal module (/core/modules/migrate_drupal). Drupal 6 data that does not fall into one of these three categories (including Views and other contrib module configuration and data) is not part of this effort.
First, some background information:
- Migrating to Drupal 8 - blog post by Claudiu Cristea - provides a great background on Drupal migrations as well as a nice overview of the process. While some of this blog post is slightly out-of-date (the project is now in Drupal core, no longer in a sandbox), the vast majority of it is still relevant.
- The Big Picture: Drupal 8 Migrate in Core - blog post by Mike Anello providing background info and details on migration configuration files.
- Technical Migration documentation - mostly up-to-date documentation of migration source, process, and destination plugins.
- End-user Migration documentation - needs updating (volunteers?)
A list of prerequisites can be found on the main How to test Drupal 6 to Drupal 8 migrations - this is a fairly standard list for Drupal 8 testing and development: PHP 5.4, Git, Drush 7.x, and a cloned version of Drupal 8. Of course, you'll also need a Drupal 6 site. If you have one lying around, you can test with that, although you might find it easier to manage if you create a fresh Drupal 6 site, add dummy content, and only test specific portions of the migration. For example, we've found more than a few bugs by starting with a fresh Drupal 6 site, adding a whole slew of profile fields of different types and settings, adding a few users, then just testing user migrations.
The How to test Drupal 6 to Drupal 8 migrations page also contains links to the two main D6->D8 migration testing meta issues (testing individual migrations and testing entire D6 site migrations) as well as tips on rolling back migrations (the old-school way), and other useful tips.
Once you're convinced that you want to help out, get your system ready to go, and pop into the #drupal-migrate room on IRC and ask to be pointed in the right direction for something to test!
I've created a couple of videos demonstrating getting your system set up as well as running a sample test - if you're new to Migrate in Core, then watching these will get you up-to-speed quickly:
Questions? Head on in to #drupal-migrate on IRC and ask away!