STR:

1. Open DevTools and select the Network panel
2. Load http://janodvarko.cz/test/websockets/
3. Click connect and send a few messages
4. Select the 101 request and open the Messages panel
5. Right click on the column header and customize columns e.g. show g. opCode
6. Clear all messages and send another mesasages -> the opCode column is gone

ER: The list of columns should stay the same.

Honza

@Harald, how the persistence should work in this case?

Should we store the columns list in prefs?

Honza

Ah, so the list of columns is actually persistent in prefs
https://searchfox.org/mozilla-central/rev/c80fa7258c935223fe319c5345b58eae85d4c6ae/devtools/client/netmonitor/src/middleware/prefs.js#103

So, this bug is only about solving the bug described in comment #0

Honza

Some instructions:

1. So, here is where we persist list of columns in prefs
   https://searchfox.org/mozilla-central/rev/c80fa7258c935223fe319c5345b58eae85d4c6ae/devtools/client/netmonitor/src/middleware/prefs.js#103

2. Here is the default state of columns
   https://searchfox.org/mozilla-central/rev/c80fa7258c935223fe319c5345b58eae85d4c6ae/devtools/client/netmonitor/src/reducers/web-sockets.js#23

3. Here is the handler for clearFrames
   https://searchfox.org/mozilla-central/rev/c80fa7258c935223fe319c5345b58eae85d4c6ae/devtools/client/netmonitor/src/reducers/web-sockets.js#112

Looks like calling the WebSocket ctor is reseting the columns and using the default state instead of the one from prefs
https://searchfox.org/mozilla-central/rev/c80fa7258c935223fe319c5345b58eae85d4c6ae/devtools/client/netmonitor/src/reducers/web-sockets.js#54

Honza