# Description
This allows plugins to report their version (and potentially other
metadata in the future). The version is shown in `plugin list` and in
`version`.
The metadata is stored in the registry file, and reflects whatever was
retrieved on `plugin add`, not necessarily the running binary. This can
help you to diagnose if there's some kind of mismatch with what you
expect. We could potentially use this functionality to show a warning or
error if a plugin being run does not have the same version as what was
in the cache file, suggesting `plugin add` be run again, but I haven't
done that at this point.
It is optional, and it requires the plugin author to make some code
changes if they want to provide it, since I can't automatically
determine the version of the calling crate or anything tricky like that
to do it.
Example:
```
> plugin list | select name version is_running pid
╭───┬────────────────┬─────────┬────────────┬─────╮
│ # │ name │ version │ is_running │ pid │
├───┼────────────────┼─────────┼────────────┼─────┤
│ 0 │ example │ 0.93.1 │ false │ │
│ 1 │ gstat │ 0.93.1 │ false │ │
│ 2 │ inc │ 0.93.1 │ false │ │
│ 3 │ python_example │ 0.1.0 │ false │ │
╰───┴────────────────┴─────────┴────────────┴─────╯
```
cc @maxim-uvarov (he asked for it)
# User-Facing Changes
- `plugin list` gets a `version` column
- `version` shows plugin versions when available
- plugin authors *should* add `fn metadata()` to their `impl Plugin`,
but don't have to
# Tests + Formatting
Tested the low level stuff and also the `plugin list` column.
# After Submitting
- [ ] update plugin guide docs
- [ ] update plugin protocol docs (`Metadata` call & response)
- [ ] update plugin template (`fn metadata()` should be easy)
- [ ] release notes
91d44f15c1