01LIVE
THE REACTOR
Promise state machine
Every promise starts pending, then settles exactly once: fulfilled or rejected.
PENDING
new Promise((resolve, reject) => {
resolve("signal found");
});
resolve("signal found");
});
{ }ASYNC//COREPROMISE NEON LAB
SYSTEM ONLINE
// JAVASCRIPT FIELD NOTES 001
Promises
in the wild.
A tiny interactive lab for watching async code change state, survive failure, and hand work to the next process.
02
THE LOOPBACK
Recursive countdown
A function can call itself. Here, each recursive pulse waits on a promise before descending.
5READY TO DESCEND
countDown(n) {
if (n === 0) return Promise.resolve();
return wait().then(() => countDown(n - 1));
}
if (n === 0) return Promise.resolve();
return wait().then(() => countDown(n - 1));
}
03
THE HAND-OFF
Callbacks into a promise
Old-school callbacks can be wrapped in a promise, giving their result a clean .then() chain.
01SCANcallback
→02DECODEpromise
→03DEPLOY.then()
Awaiting payload...
OBSERVABILITY
Event stream
TRACE
Lab initialized. Choose a signal.