So code that was untested (the code path that failed was never exercised), perhaps there is no test environment, and not even peer reviewed ( it did not have appropriate error handling nor was it feature flag protected.) was pushed to production, what a surprise !!
There absolutely is a test environment, it was absolutely reviewed and Google has absolutely spent Moon-landing money on testing and in particular static analysis.
Moon landing money on static analysis that failed to identify the existence of a completely untested code path? Or even to shake this out with random data generation?
This is a dumbfounding level of mistake for an organization such as Google.
What makes you think it was completely untested?
The condition that triggered the null pointer exception was obviously not tested, but it doesn't mean it didn't have tests or even 100% unit test coverage for the coverage tools.
In addition it looks like the code was not ready for production and the mistake was not gating it behind a feature flag. It didn't go through the normal release process.
If Google spent Moon-landing level of money in their quality/deployment infrastructure I expect a much better coverage checker than "100% unit tested", they are famous for having a whole fuzzing infrastructure, coverage analysers for more complex interplay of logic is something I use daily in a non-Google levels of spending (even though still a big enough corporation) which often reminds me that I forgot to write a functional test to cover a potential orchestration issue.
I don't think "completely untested" is correct but tested way below expectations for such structural piece of code is a lesson they should learn, it does look like an amateur-hour mistake.
The main issues to me seem to be that the code was not gated by a flag when it was not ready to be used, thus skipping a lot of the testing / release qualification.
