Author: Adrienne Walker and Raphaël Moll (colleagues of Nathaniel's at Google)

Appeal To Importance

This needs to land this right now to fix a bug / make a milestone / my hair’s on fire; can‘t you understand that there’s no time for tests??

Sufficient Coverage Argument

This CL already has at least one unit test, and therefore should be considered reasonably tested.

Argument From Historical Laziness

This other pre-existing system doesn’t have tests, so my similar new system shouldn’t need any either!

Missing Infrastructure Argument

There’s no good way to write these tests easily, so I shouldn’t need to write them.

Insufficient Coverage Argument

The tests requires extensive mocking (of servers, RPCs, filesystems, 3d party libs with their own side-effects, GUI) and would thus not test the real system but a limited fictional subsystem. Such tests would be totally irrelevant so they need not be written.

Just a Refactoring Argument

All functionality in this patch is already entirely covered by preexisting tests. Trust me.

Promise Of Future Work

I pinky-swear that I will write a follow-up CL that adds tests, just as soon as I fix these other things first...

The Proof is in the Pudding

We‘re already using this for releases. It clearly works so we don’t need to write tests. At this point we empirically have full coverage and just found a couple minor bugs.