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I seriously doubt it is actually 100%... let's verify that number.


When I was at Amazon, the general consensus was 90-95% but not higher. We also excluded all of our Java Spring/Guice configs.


Just what I thought, thanks for the confirmation. HN loves to take a number and just run with it, without verifying anything.


No, my requirement was actually 100%. I have no reason to lie about this. It’s set at a package level.


Was this just you or everyone on your team?


everybody on my team. Are you seriously implying I was put on some kind of special "extra testing required" probation system where the unit test coverage requirement was upped from 95% to 100%?

Are you trolling?


It sounds kind of absurd really. I've never once been asked to sign a contract that required me to do 100% code coverage. As others have noted in the thread, it is like some mythical number any way. It sounds to me like this wasn't going to end well since the expectations were wonky from the start.


https://jestjs.io/docs/configuration#coveragethreshold-objec...

It is absolutely possible to set the coverage threshold in Jest to 100% for all categories and they are set to that in the codebase I worked on. I would spend hours trying to that last 0.02% covered sometimes.


The mythical portion of the number is that last 0.02%... the stuff that is just extra work for no logical benefit.

It does make me wonder why it would take you hours to do that though... was the code that complicated to test for some reason?


Yes, it was. It used a very obscure language feature of JavaScript. I won't get more detailed than that.


I still don't understand why that would cause testing to be hard, but since you won't explain it... I guess it leaves me thinking the problem might not be entirely them.


It's quite possible to get line coverage to 100%. It doesn't really mean anything because it might be covering those lines getting executed in one very particular order - and all bets are off if that order is different.


on our team it was more "Don't lower it, get accolades for increasing it", and someone gamed it up to 100% using the methods I described.




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