fs.watch doesn't listen changes of file containing JSON stringified if changes happen too quickly (behavior different with non JSON)

[Apokalypt]

Version

v20.11.0

Platform

23.2.0 Darwin

Subsystem

node:fs

What steps will reproduce the bug?

const fs = require('fs');
const path = require('path');

const filePath = path.join(__dirname, 'test.json');
// Create the file if it doesn't exist
if (!fs.existsSync(filePath)) {
    fs.writeFileSync(filePath, "{ }");
}

fs.watch(filePath, (eventType, filename) => {
    console.log(`Event type is: ${eventType}`);
    if (filename) {
        console.log(`Filename provided: ${filename}`);
    } else {
        console.log('Filename not provided');
    }
});

fs.writeFileSync(filePath, "{ \"test\": \"test\", \"test2\": \"test2\" }"); // same with JSON.stringify(...)
// Listener above is called if we replace line above with:
// fs.writeFileSync(filePath, "very ok or not but I need a longer text to test something...");

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

With the code above it happens all the time. But if you change the content of the file to normal string (not JSON stringified) it seems to happen only few times but I don't know why...

Something to keep in mind is that if we add a delay before updating the file, it will always be detected (JSON stringified or not)

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

Event type is: change
Filename provided: test.json

What do you see instead?

Nothing

Additional information

I wanted to watch changes on a file storing JSON stringified data but the listener passed in fs.watch is not called if the change happen too quickly after the call of fs.watch. The strange thing is that if the content is only a text (without JSON format) the watcher emit the event correctly...

I have tested this behavior on different version of node :

• v20.11.0
• v18.17.1
• v16.20.1

Before creating this issue here, I created a help request ( #53111 ) where other members confirmed this strange behavior

[MoLow]

this is probably a libuv issue. @nodejs/libuv @nodejs/fs