Testing to provide reliability
If you take away only one thing from this section, please be it this: “Tests are going to be your sleep-well-at-night superpower.”
Tests ensure that things go as you wish them to go and alert you when that’s not true.
They are your army, protecting your work and time from the evil influences of broken data sources and the inevitable code bugs (yours and from your colleagues).
That’s real power.
Lack of testing compounded with development without rigor, as people writing SQL queries often lack a software engineering background, makes firefighting issues the most common activity in too many data teams, and the idea of changing some heavily used part of the data pipelines (think customers or orders) can make a whole team sweat. Ever been there?
We want you to be free of these nightmares. In the previous chapters, we provided sound guidelines on how to organize your code and make it easy to read and maintain. In...