Filtering "Exclude" shows wrong weekday

[flamber]

Describe the bug
Filtering "Exclude" shows wrong weekend - though, the actual query is correct - took me a while to understand what was going on.

To Reproduce

1. Question > Sample > Products
2. Filter CreatedAt > Exclude > "Days of the week" > uncheck Monday - Add filter
3. Incorrectly shows the wrong day - it is filtering correctly in the query
   
4. Edit the filter and select Monday again, now it's not possible the save the filter changes (Update filter)
   

Expected behavior
While I'm fine with the order of the weekdays, then in a perfect world, it should order depending on Admin > Settings > Localization > First day of the week

Information about your Metabase Installation:
0.43.0-rc1 and master b9cedcc

[akiselev]

@flamber what is the correct behavior for the second part?

If the user selects nothing to exclude, the resulting filter would be ["!=", ["field", ...]] which isn't a valid expression. Update filter in this case should remove the filter altogether in order to keep it valid?

[flamber]

@akiselev I would expect to be able to deselect and select something again.
If it should remove the filter or now, perhaps, I'm not sure.

[akiselev]

@flamber Only ["!=", ["field", ...], null] works without removing the filter altogether but I'm not sure about the semantics. Does setting 'temporal-unit' along with != null result in a field is not null?

[flamber]

@akiselev I don't know the code, so probably better if you ask one of the BE devs.

[akiselev]

@flamber is extract(day_of_week FROM my_field) IS NOT NULL acceptable semantics here when nothing is excluded? Otherwise I think we'll have to remove the filter

[flamber]

@akiselev If it makes more sense to remove the filter, then do that. You should ask someone who has been part of the team working on this feature, since I don't know what the intention was, but perhaps it's somewhere in Notion.