App sync error: expected a string but was BEGIN_ARRAY

[GeorgeHahn]

Issue details

Part of the way through initial sync on my device, the sync process halts and an error is shown in the notification drawer. The sync process does not continue and no items are shown.

Error:

Error: com.squareup.moshi.JsonDataException: Expected a string but was BEGIN_ARRAY at path $._embedded.items[4].published_by[0]

Environment

Wallabag version: 2.3.8
Installation method: Docker (running latest tag, f6b2b6b2a1fd)
Running on a local network server
Database: SQLite

Steps to reproduce/test case

Sync with android app version 2.3.0 (219), observe failure midway through sync.

[GeorgeHahn]

I followed the app sync to find the item causing this failure. Here's the entry where the error occurs (many fields omitted):

{
    "page": 30,
    "limit": 30,
    "_embedded": {
        "items": [
            {
                // this is items[4]:
                "url": "https://www.newyorker.com/books/under-review/the-bullshit-job-boom",
                "published_by": [
                    [
                        "Nathan Heller"
                    ]
                ]
            }
        ]
    }
}

The WebUI displays this article like so:

[anarcat]

i am also getting this error on full sync, which is a big problem because it breaks sync for new devices completely... here is my backtrace:

https://paste.anarc.at/publish/2020-09-09-RbW8ARAMnriRw4H0UC6lLhQIigsd7HDkT2OpaxUDSf0/stdin.txt

it would be nice if wallabag at least handled that exception correctly...

[di72nn]

This comment explains how to fix this.

[anarcat]

yeah, but that requires server access, which people might not necessarily have

[di72nn]

Self-hosting users should be able to deal with it themselves. Users of hosted solutions (wallabag.it, etc.) should ask server administrator to deal with it. Am I missing some other category?

[anarcat]

i guess my argument is that even server admins might not be aware of the problem or might not clearly see how to fix it, because it's not part of release notes or documented other than in issues such as this one.

i'll also note that this issue is filed against the server side, and still open. I would argue it should be fixed by shipping a database migration that corrects this problem and wallabag/android-app#890

[j0k3r]

Both bug should be fixed with 2.4.0 I guess. Can someone confirm?

[solkaz]

@j0k3r @di72nn I still am encountering this issue on 2.4.2 (Pixel 3a, Android 11, using app.wallabag.it)

Edit: the published_by value in this case is

"published_by": [
  ""
],

The URL is https://baymard.com/blog/custom-dropdowns-cause-issues

[di72nn]

I still am encountering this issue

It should be fine if you refetch the article.

I believe fetching is fixed, but the old data may still be broken.

[nicosomb]

@GeorgeHahn @di72nn hello. Could you try with latest wallabag version and tell us if this bug still occurs please?

[GeorgeHahn]

Sorry, I don't use Wallabag anymore and will be unable to test this.

[solkaz]

@nicosomb this issue still is present for me (edit: I am using app.wallabag.it)

[virtadpt]

Still broken for me.