·10 min read
One BigInt in your log data deletes every other field
One BigInt makes JSON.stringify throw, so your logger drops every other field too. What I measured, and a safe() helper that keeps Dates and Errors intact.
❯grep -rl "#nodejs" ./posts
#nodejs
4 posts
·7 min read
Your fetch timeout starts before the request does
AbortSignal.timeout() starts counting when you create it, not when fetch runs. In a queue or retry loop it quietly kills requests still waiting their turn.
·9 min read
What really happens when two requests share one console.time() label
Everyone says console.time() breaks under concurrency because the second call overwrites the first. I tested it in Node, Bun and Deno, and that is not what happens. The second timer is thrown away, the fast request reports the slow request's duration, and the slow request reports nothing at all.
·18 min read
How to tag every log line with a request ID using AsyncLocalStorage (and the 3 places it silently gives you nothing)
AsyncLocalStorage lets you stamp a request ID onto every log line without passing it through every function. But it can fail without throwing a single error — so your logs just quietly lose the ID. Here are the three cases I reproduced, and the two-minute check that catches them.