Performance issue with Date.toLocaleString in Node.js

[OguzhanUmutlu]

Version

v19.8.1

Platform

Microsoft Windows NT 10.0.22621.0 x64

Subsystem

No response

What steps will reproduce the bug?

Run the following code in Node.js:

const date = new Date;

console.time();
const str = date.toLocaleString("en", {month: "short", day: "numeric"});
console.timeEnd();

console.log(str);

How often does it reproduce? Is there a required condition?

The issue reproduces consistently every time the code is executed.

What is the expected behavior? Why is that the expected behavior?

The expected behavior is that the execution time of date.toLocaleString should be reasonably fast, comparable to the performance observed in web browsers. It should be able to perform this relatively simple task efficiently.

What do you see instead?

When running the code in Node.js, the execution time of date.toLocaleString is observed to be significantly slower compared to running it in a web browser. The reported execution time is around 20-30 milliseconds, which is much longer than expected for such a straightforward operation. In contrast, when executed in a browser environment, the same code completes in approximately 0.3-0.4 milliseconds.

Additional information

No response

[OguzhanUmutlu]

Note: It's the same no matter what are the options.(Tried with no options and got the same 20-30 milliseconds result)

[anonrig]

Hi @OguzhanUmutlu, we are tracking a similar issue on nodejs/performance repository: nodejs/performance#47

[bnoordhuis]

The test case is defective. V8 does some one-time setup the first time you call toLocaleString(). All subsequent calls take <1ms. Closing.