The streaming-update-common project contains a unit test (MutationEventDataJsonSerializationUnitTest), which makes a network call to https://schema.wikimedia.org to fetch a JSON schema for validation. This test fails when run in environments with network restrictions, and occasionally the request times out in CI, causing builds to fail.

As a wdqs maintainer I want to run the test suites without an access to internet so that I can build the project on restricted environments like the stats machines.

AC:

• MutationEventDataJsonSerializationUnitTest loads the required schema from a local fixture.
• The build passes on stat1010.eqiad.wmnet