Tag: correctness
All the articles with the tag "correctness".
Three bugs, one root cause: the label was not the identity
A rendering layer derives a human label from a machine identity. Both are strings. The type checker has nothing to say and the money path does.
Your error handler is inside the cache
A container restart took thirty seconds. The site stayed broken for an hour after it came back.
Idempotent writes don't make side effects idempotent
The upsert was the easy half. The write also caused four other things, and none of them were idempotent for free.
Math.floor is not a floor
The obvious fix drops a step. The clever fix rounds past the input. Neither raises an exception, and only one of them spends money you don't have.