The default for Supported Book Formats (`epub, mobi, azw3, fb2, djvu,
cbz, cbr`) was written out in five places: the settings registry,
`postprocess/policy.py`, `irc/parser.py`, Prowlarr's `source.py` (added
in #1490) and slskd's `source.py` (added in #1428). Both of those two
arrived in 1.5.0, and both are mine, so this is cleaning up after myself
as much as anything.
The setting was also read three different ways. Post-processing split on
commas only. slskd split on commas and spaces and stripped a leading
dot. IRC split on commas and kept the dot. Prowlarr split on commas and
kept `""` as a format when the value was an empty string. So `.epub` or
`epub mobi` worked in one source and not another.
This puts `DEFAULT_EBOOK_FORMATS` and `normalize_format_list` in
`core/utils.py` next to `AUDIOBOOK_FORMATS`, and the registry,
post-processing, IRC, Prowlarr and slskd all use them. I took the most
lenient reading of the three (comma or space split, leading dot dropped,
empties ignored, default when nothing is left), so no existing config
gets stricter. I put the reader in `core/utils.py` and not in
`policy.py` because the release sources can't import `policy` without
pulling in the whole post-processing package.
A config with a sensible list reads exactly as before. The only
differences are for malformed values: an emptied setting or an empty
string now falls back to the default in every place, where IRC used to
filter everything out and Prowlarr treated `""` as a format.
The audiobook default is a separate story and I left it alone: the
registry and slskd default to every processable audiobook format plus
the archives, while post-processing and IRC fall back to `m4b, mp3`.
They only differ when the setting is unset or emptied, but they do
differ, and I'd rather ask which one you want than pick one here.
Ruff, basedpyright on the changed files and the backend suite pass (4400
passed, e2e not run). New tests cover the reader and the two fallbacks.
