ABTest query parameter

Background

From https://jira.eyeo.com/browse/ABC-160

We want to perform AB testing with filter list. For that we need to pass the abtest parameter from the filter list.

In the subscription list we receive ! ABTest: id where id is the test id.

The id is sent back with the HTTP query parameter abtest=id when downloading the subscription.

What to change

• In Synchronizer.parseFilters() allow the ABTest param, only for filter lists that are in the recommended subscription list.
• In the synchronizer pass the parameter back to the query.

Notes

Things that should be clarified:

• Define the kind of data the id is.
• What can potentially go wrong and how can that be abused?
  • we restrict this to filter lists in the default subscriptions.

Note for testers

TBD