Many of our changes will be safe to deploy immediately, and will handle legacy maps traffic.
Do not merge anything until we have the full migration planned, see T293843.
Make sure all patches that go to master have tests added, if possible.
* [] mapdata repo
* [x] Integrate a unit testing framework: jest
* [x] Add unit tests to cover legacy title logic
* [x] Add unit test for revid logic
* [] Enable tests in CI
* [] Kartographer
* [] Cover legacy mapdata API with tests
* [] Cover new revid logic with tests
* [] Kartotherian
* [] Cover legacy mapdata pass-through
* [] Cover revid pass-through with tests
* [] Test feature flag for killing revid pass-through
* [] varnish
* [] Write varnishtest to cover the hash calculation
* [] Test that revid URLs hash to the same as a legacy URL without revid.
* [] Test that revid regsub cannot be fooled by parameter order, invalid, or missing values