PackagesGeneral Lib
Promise Utilities
Documentation for promise-related helper utilities.
promiseMap
A convenient shorthand for Promise.all(array.map(callback)). It iterates over an array, applies an async callback to each item, and returns a promise that resolves to an array of the results.
Usage
This is used in @backend/core to serialize a list of models.
import { promiseMap } from "@localspace/lib";
const userIds = [1, 2, 3];
const users = await promiseMap(userIds, async (id) => {
const user = await User.find(id);
return user.transformer.serialize();
});
// `users` is now an array of serialized user objectstryPromise
This utility wraps a promise and returns a tuple of [result, error], similar to Go's error handling pattern. This allows you to handle promise rejections without a try...catch block, which can be useful for cleaner inline error handling.
Usage
import { tryPromise } from "@localspace/lib";
async function mightFail(shouldFail: boolean): Promise<string> {
if (shouldFail) {
throw new Error("Operation failed");
}
return "Success!";
}
// --- Success Case ---
const [result, error] = await tryPromise(mightFail(false));
if (error) {
// This block is not executed
console.error("Caught an error:", error);
} else {
console.log("Got a result:", result); // -> 'Got a result: Success!'
}
// --- Failure Case ---
const [result2, error2] = await tryPromise(mightFail(true));
if (error2) {
console.error("Caught an error:", error2.message); // -> 'Caught an error: Operation failed'
} else {
// This block is not executed
}sleep
An asynchronous sleep function that resolves a promise after a specified number of milliseconds.
Usage
import { sleep } from "@localspace/lib";
async function runWithDelay() {
console.log("Starting...");
await sleep(1000); // Wait for 1 second
console.log("Finished after 1 second.");
}