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b5e09b8a30
r? @fdncred
Last one, I hope. At least short of completely redesigning `registry
query`'s interface. (Which I wouldn't implement without asking around
first.)
# Description
User-Facing Changes has the general overview. Inline comments provide a
lot of justification on specific choices. Most of the type conversions
should be reasonably noncontroversial, but expanding `REG_EXPAND_SZ`
needs some justification. First, an example of the behavior there:
```shell
> # release nushell:
> version | select version commit_hash | to md --pretty
| version | commit_hash |
| ------- | ---------------------------------------- |
| 0.85.0 | a6f62e05ae5b4e9ba4027fbfffd21025a898783e |
> registry query --hkcu Environment TEMP | get value
%USERPROFILE%\AppData\Local\Temp
> # with this patch:
> version | select version commit_hash | to md --pretty
| version | commit_hash |
| ------- | ---------------------------------------- |
| 0.86.1 | 0c5a4c991f1a77bcbe5a86bc8f4469ecf1218fe9 |
> registry query --hkcu Environment TEMP | get value
C:\Users\CAD\AppData\Local\Temp
> # Microsoft CLI tooling behavior:
> ^pwsh -c `(Get-ItemProperty HKCU:\Environment).TEMP`
C:\Users\CAD\AppData\Local\Temp
> ^reg query HKCU\Environment /v TEMP
HKEY_CURRENT_USER\Environment
TEMP REG_EXPAND_SZ %USERPROFILE%\AppData\Local\Temp
```
As noted in the inline comments, I'm arguing that it makes more sense to
eagerly expand the %EnvironmentString% placeholders, as none of
Nushell's path functionality will interpret these placeholders. This
makes the behavior of `registry query` match the behavior of pwsh's
`Get-ItemProperty` registry access, and means that paths (the most
common use of `REG_EXPAND_SZ`) are actually usable.
This does *not* break nu_script's
[`update-path`](https://github.com/nushell/nu_scripts/blob/main/sourced/update-path.nu);
it will just be slightly inefficient as it will not find any
`%Placeholder%`s to manually expand anymore. But also, note that
`update-path` is currently *wrong*, as a path including
`%LocalAppData%Low` is perfectly valid and sometimes used (to go to
`Appdata\LocalLow`); expansion isn't done solely on a path segment
basis, as is implemented by `update-path`.
I believe that the type conversions implemented by this patch are
essentially always desired. But if we want to keep `registry query`
"pure", we could easily introduce a `registry get`[^get] which does the
more complete interpretation of registry types, and leave `registry
query` alone as doing the bare minimum. Or we could teach `path expand`
to do `ExpandEnvironmentStringsW`. But REG_EXPAND_SZ being the odd one
out of not getting its registry type semantics decoded by `registry
query` seems wrong.
[^get]: This is the potential redesign I alluded to at the top. One
potential change could be to make `registry get Environment` produce
`record<Path: string, TEMP: string, TMP: string>` instead of `registry
query`'s `table<name: string, value: string, type: string>`, the idea
being to make it feel as native as possible. We could even translate
between Nu's cell-path and registry paths -- cell paths with spaces do
actually work, if a bit awkwardly -- or even introduce lazy records so
the registry can be traversed with normal data manipulation ... but that
all seems a bit much.
# User-Facing Changes
- `registry query`'s produced `value` has changed. Specifically:
- ❗ Rows `where type == REG_EXPAND_SZ` now expand `%EnvironmentVarable%`
placeholders for you. For example, `registry query --hkcu Environment
TEMP | get value` returns `C:\Users\CAD\AppData\Local\Temp` instead of
`%USERPROFILE%\AppData\Local\Temp`.
- You can restore the old behavior and preserve the placeholders by
passing a new `--no-expand` switch.
- Rows `where type == REG_MULTI_SZ` now provide a `list<string>` value.
They previously had that same list, but `| str join "\n"`.
- Rows `where type == REG_DWORD_BIG_ENDIAN` now provide the correct
numeric value instead of a byte-swapped value.
- Rows `where type == REG_QWORD` now provide the correct numeric
value[^sign] instead of the value modulo 2<sup>32</sup>.
- Rows `where type == REG_LINK` now provide a string value of the link
target registry path instead of an internal debug string representation.
(This should never be visible, as links should be transparently
followed.)
- Rows `where type =~ RESOURCE` now provide a binary value instead of an
internal debug string representation.
[^sign]: Nu's `int` is a signed 64-bit integer. As such, values >=
2<sup>63</sup> will be reported as their negative two's compliment
value. This might sometimes be the correct interpretation -- the
registry does not distinguish between signed and unsigned integer values
-- but regedit and pwsh display all values as unsigned.