Zed is caching files?

[shinebayar-g]

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Describe the bug / provide steps to reproduce it

I'm using VSCode & Zed at the same time. Testing it hand by hand. It seems Zed is caching files aggressively.

1. Open the same file foo.json in both VSCode and Zed at the same time.
2. Edit the file in VSCode.
3. Zed doesn't see the change. Usually it sees the change without even closing the active editor tab. But this time it doesn't.
4. I even tried closing the active editor tab and re-opened the same file from the file tree. But Zed still doesn't see the change.
5. The only way to see the change was to reload the Zed or restart Zed.

It's not reproducible in small files. The file I was working on was 30MB big json file. So I'm assuming file size may has something to do with it.

Environment

Zed: v0.162.2 (Zed Preview)
OS: macOS 15.1.0
Memory: 16 GiB
Architecture: aarch64

If applicable, add mockups / screenshots to help explain present your vision of the feature

No response

If applicable, attach your Zed.log file to this issue.

Zed.log

[jknlsn]

Seeing the same behaviour, in a .json file just over 2MB

[notpeter]

Can you provide explicit steps to reproduce? Are you saving the file in VSCode?
When I save changes to a big JSON file in VSCode Zed immediately picks up the changes.

[shinebayar-g]

Sure, I'll try to prepare exact steps to reproduce with sample data.

[jknlsn]

In my case it was a separate script modifying the JSON, that I had open in Zed to monitor/change manually if needed.

I've just tried to write a simple script now to simulate this, but I'm not able to reproduce the exact behaviour, I'm not seeing it currently. The file is similar in size by making a minimum 3000 entries. Ramping the number up to 30000 entries doesn't seem to make a difference.
I don't know if it was to do with any other apps I had open etc, memory pressure, or version of Zed.

Anyway here's the script to give you an idea, just in case it's a starting point.

import json
import random
import string
from pathlib import Path

FIRST_NAMES = ['Emma', 'Liam', 'Olivia', 'Noah', 'Ava', 'Ethan', 'Sophia', 'Mason', 'Isabella', 'William']
LAST_NAMES = ['Smith', 'Johnson', 'Williams', 'Brown', 'Jones', 'Garcia', 'Miller', 'Davis', 'Rodriguez', 'Martinez']
DEPARTMENTS = ['science', 'math', 'history', 'english', 'art']

def generate_random_id():
    return f"{random.choice(DEPARTMENTS)}_{random.choice(LAST_NAMES).lower()}_{random.randint(1000, 9999)}"

def generate_entry():
    first_name = random.choice(FIRST_NAMES)
    last_name = random.choice(LAST_NAMES)
    dept = random.choice(DEPARTMENTS)

    return {
        "name": f"{first_name} {last_name}",
        "class": dept,
        "email": f"{first_name.lower()}.{last_name.lower()}@school.edu",
        "group": f"group_{random.randint(1, 5)}",
        "status": random.choice(['active', 'inactive', 'pending'])
    }

def generate_test_data(filename='test_data.json'):
    data = {}

    if Path(filename).exists():
        with open(filename, 'r') as f:
            data = json.load(f)

    current_count = len(data)
    if current_count < 3000:
        entries_to_add = 3000 - current_count
    else:
        entries_to_add = random.randint(5, 25)
    for _ in range(entries_to_add):
        student_id = generate_random_id()
        while student_id in data:  # Ensure unique ID
            student_id = generate_random_id()
        data[student_id] = generate_entry()

    with open(filename, 'w') as f:
        json.dump(data, f, indent=2)

    return len(data)

if __name__ == "__main__":
    final_count = generate_test_data()
    print(f"Test data generated. Total entries: {final_count}")

[notpeter]

If you manage to trigger this behavior again, please see if there's anything of note in the Zed logs.

Pure speculation, but I wonder if there's a race condition where Zed gets notified of a change but before we can read the filename is replaced again. As a result Zed falls into an error state when it stops watching. (pure speculation). I'd be curious whether closing and reopning the tab (cmd-w, cmd-shift-t) brings things back to normal.

Anyways, would love something reproducible so we can dig deeper.