Data engineering·Quality, tests and knowing it is wrong
the transform ships with a check that this column is never null, and the check runs against real output every night rather than against a fixture.
Data test
Also calleddata assertion, model test
An assertion evaluated against actual data in the warehouse, rather than against code. It is a fundamentally different thing from a unit test: the code did not change, the input did, so it must run on every load rather than in CI. That also means it can fail at 03:00 for reasons nobody controls, which is why every data test needs a decision attached about whether failing it stops the pipeline.