Inquiry Regarding Index Data Format and EINVAL Error

[ayoubbif]

Hi,

I'm working with ZenFS and have encountered an issue while trying to initialize the file system. Specifically, I’m receiving the following error:

Failed to initialize file system: EINVAL: Incorrect type for "index": string (expected one of string, object)

Based on the error message, it seems the "index" passed into the resolveMountConfig function might not be in the expected format.

I’m using the following structure for the indexData (based on the IndexData interface from the documentation):

interface IndexData {
    entries: Record<string, StatsLike<number>>;
    version: number;
}

Here’s an example of the indexData I’m passing:

{
  "entries": {
    ".index": { "mode": 16877, "size": 4096, "mtime": 1736270682359 },
    "files": { "mode": 16877, "size": 4096, "mtime": 1736265140681 },
    "icons": { "mode": 16877, "size": 4096, "mtime": 1736167012567 }
  },
  "version": 4,
  "size": 18631
}

I’ve confirmed that the indexData is being properly parsed and passed as an object to resolveMountConfig. However, I’m still encountering the error. I’d appreciate your guidance on whether this JSON format is correct and why I might be receiving this EINVAL error.

Is the expected index format a string or an object in this context? If it should be an object, is there something else I might be missing in how the data is passed?

Looking forward to your response!

[james-pre]

Hi @ayoubbif, thanks for reaching out!

What does your configuration look like?

Also, for the JSON data, you can use the make-index script (npx make-index). For help, you can run npx make-index --help. This will generate an index.json file for you with all the correct info.

[ayoubbif]

Hi @james-pre,
Thank you for your quick response!

I use the following to initialize the file system in my application:

import { configure, fs, resolveMountConfig, Overlay, Fetch } from "@zenfs/core";
import { IndexedDB } from "@zenfs/dom";

useEffect(() => {
  const initializeFileSystem = async () => {
    try {
      // Fetch the index file and parse it into an object
      const indexResponse = await fetch(".index/fs.zen.json");
      const indexData = await indexResponse.json();

      // Resolve mount configurations
      const readable = await resolveMountConfig({
        backend: Fetch,
        index: indexData,
      });

      const writable = await resolveMountConfig({
        backend: IndexedDB,
        storeName: "zenfs-cache",
      });

      // Configure the file system
      await configure({
        mounts: {
          "/": {
            backend: Overlay,
            readable,
            writable,
          },
        },
      });

      setFsState({ fs, isReady: true });
    } catch (error) {
      console.error("FileSystem initialization error:", error);
    }
  };

  initializeFileSystem();
}, []);

Thank you for recommending make-index I tried using it, but that didn't resolve the issue.

[ayoubbif]

I'm using 1.7.2 and 1.1.3, and I've tried reproducing my implementation only using vanilla typescript and I still get the same error unfortunately.

[james-pre]

@ayoubbif That's odd... could you please create a minimally reproducible example, without React? Also, please include the directory structure and exact make-index command? Also, you can make the config simpler:

import { resolveMountConfig, configureSingle, Fetch, Overlay, InMemory } from '@zenfs/core';
import { IndexedDB } from '@zenfs/dom';

// configureSingle can be used if you only need to change the root mount
await configureSingle({
	backend: Overlay,
	// the `Fetch` backend can fetch the index for you, so you don't have to do the manual parsing
	readable: await resolveMountConfig({ backend: Fetch, index: '.index/fs.zen.json' }),
	writable: await resolveMountConfig({ backend: IndexedDB, storeName: 'cache' }),
});

[ayoubbif]

@james-pre I used this exact example you just provided me.

Here's the command I use for generating the fs.zen.json file: cd public && npx make-index -o .index/fs.zen.json

Here's the error I am getting:
Uncaught Error: Incorrect type for "index": string (expected one of string, object)

[james-pre]

This is a bug with ZenFS when a backend allows multiple types for a configuration option. A patch will be released soon.

[james-pre]

Fixed in 057cb42.