Crashes if there are canvases in the dump

[nneonneo]

Some of our channels had canvases in them, which are saved as files called _channels/[cid]/canvas_in_the_conversation.json (as opposed to files named using YYYY-MM-DD.json, like all other messages).

Instead of containing messages, this file contains file entries that look like this:

[
{
    "id": "F0...",
    "created": 16...,
    "name": "Untitled",
    "title": "Untitled",
    "mimetype": "application\/vnd.slack-docs",
    "filetype": "quip",
    "pretty_type": "Canvas",
    "user": "USLACKBOT",
    "editable": true,
    "size": 35,
    "mode": "quip",
    "is_public": true,
    "is_tombstoned": false,
    "public_url_shared": false,
    "date_delete": 0,
    "url_private_download": "https:\/\/files.slack.com\/files-pri\/...",
    "shares": [
        {
            "team": "T0...",
            "channel": "C1..."
        }
    ]
}
]

Unfortunately, wayslack tries to read these as messages, and crashes with the following exception:

Traceback (most recent call last):
  File "/Library/Frameworks/Python.framework/Versions/3.10/bin/wayslack", line 8, in <module>
    sys.exit(main())
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/wayslack.py", line 1513, in main
    archive.refresh()
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/wayslack.py", line 1293, in refresh
    sub.refresh()
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/wayslack.py", line 889, in refresh
    BaseArchiver.refresh(self)
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/wayslack.py", line 821, in refresh
    obj.refresh()
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/wayslack.py", line 576, in refresh
    self._refresh_messages()
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/wayslack.py", line 682, in _refresh_messages
    last_saved_replies_ts = get_last_saved_replies_ts()
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/wayslack.py", line 618, in get_last_saved_replies_ts
    for msg in sorted(self.load_messages(archive), key=lambda m: m["ts"], reverse=True):
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/wayslack.py", line 618, in <lambda>
    for msg in sorted(self.load_messages(archive), key=lambda m: m["ts"], reverse=True):
KeyError: 'ts'

In my case, I just deleted these canvas_in_the_conversation.json files after verifying the files they pointed to were empty canvases (just people pressing the button by accident). However, a more general solution should be to ignore these files completely.

[huyz]

I'll try to take a look within the next week or two