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salomonk_murtoday at 12:27 PM1 replyview on HN

If one is flaky, then you are below 100% friend.


Replies

alkonauttoday at 12:41 PM

That's not what I mean. I mean that anything but 100% is a "stop the world this is unacceptable" kind of event. So if there is a day when there is a flaky test, it must be rare.

To explain further

There is a difference between having 99.99% test pass every day (unacceptable) which is also 99.99% tests passing for the year, versus having 100% tests passing on 99% of days, and 99% tests on a single bad day. That might also give 99.99% test pass rate for the year, but here you were productive on 99/100 days. So "100.0 is the normal" is what I mean. Not that it's 100% pass on 100% of days.

Having 99.98% tests pass on any random build is absolutely terrible. It means a handful of tests out of your test suite fail on almost _every single CI run_. If you have 100% test pass as a validation for PR's before merge, that means you'll never merge. If you have 100% test pass a validation to deploy your main branch that means you'll never deploy...

You want 100% pass on 99% of builds. Then it doesn't matter if 1% or 99% of tests pass on the last build. So long as you have some confidence that "almost all builds pass entirely green".