Fallback to databases in inspect-data.json when no -i options are passed

[frankier]

Currenlty Datasette.__init__ checks immutables against None to decide whether to fallback to inspect-data.json. This patch modifies the serve command to pass None when no -i options are passed so this fallback works correctly.

[codecov]

Codecov Report

Merging #1031 into main will decrease coverage by 0.02%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main    #1031      +/-   ##
==========================================
- Coverage   84.63%   84.60%   -0.03%     
==========================================
  Files          28       28              
  Lines        3892     3892              
==========================================
- Hits         3294     3293       -1     
- Misses        598      599       +1     

Impacted Files	Coverage Δ
datasette/cli.py	74.22% <ø> (ø)
datasette/views/index.py	96.49% <0.00%> (-1.76%)	⬇️

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[simonw]

I don't fully understand the bug you're fixing here. Could you provide a bit more explanation?

[frankier]

The bug is that currently when there are databases passed in, but no -i flag, e.g. in configuration directory mode, inclusion in inspect-data.json does not automatically cause databases to be considered immutable, as described in the documentation.

The reason is that the -i flag is specified multiple=True, which means when it is not passed in we will get an empty list [], rather than None. So the current code decides that no databases are immutable rather than falling back to inspect-data.json -- as is presumably intended.

[frankier]

Please let me know if there's anything I can do to help get this merged.

This is causing problems for me because it means when I build my Docker image my databases aren't considered immutable, which I would like them to be so that a download link is produced.

[simonw]

This bug should have been fixed in #1229 - let me know if that's not the case!

Thanks

[simonw]

Sorry I didn't get to this PR sooner. I've joint-credited you in the release notes for this fix: https://docs.datasette.io/en/stable/changelog.html#v0-56