# Description
Currently, all four of these commands return a (rather-confusing)
spanless error when passed an empty list:
```
> [] | sort
Error:
× no values to work with
help: no values to work with
```
This PR changes these commands to always output `[]` if the input is
`[]`.
```
> [] | sort
╭────────────╮
│ empty list │
╰────────────╯
> [] | uniq-by foo
╭────────────╮
│ empty list │
╰────────────╯
```
I'm not sure what the original logic was here, but in the case of `sort`
and `uniq`, I think the current behavior is straightforwardly wrong.
`sort-by` and `uniq-by` are a bit more complicated, since they currently
try to perform some validation that the specified column name is present
in the input (see #8667 for problems with this validation, where a
possible outcome is removing the validation entirely). When passed `[]`,
it's not possible to do any validation because there are no records.
This opens up the possibility for situations like the following:
```
> [[foo]; [5] [6]] | where foo < 3 | sort-by bar
╭────────────╮
│ empty list │
╰────────────╯
```
I think there's a strong argument that `[]` is the best output for these
commands as well, since it makes pipelines like `$table | filter
$condition | sort-by $column` more predictable. Currently, this pipeline
will throw an error if `filter` evaluates to `[]`, but work fine
otherwise. This makes it difficult to write reliable code, especially
since users are not likely to encounter the `filter -> []` case in
testing (issue #5957). The only workaround is to insert manual checks
for an empty result. IMO, this is significantly worse than the "you can
typo a column name without getting an error" problem shown above.
Other commands that take column arguments (`get`, `select`, `rename`,
etc) already have `[] -> []`, so there's existing precedent for this
behavior.
The core question here is "what columns does `[]` have"? The current
behavior of `sort-by` is "no columns", while the current behavior of
`select` is "all possible columns". Both answers lead to accepting some
likely-buggy code without throwing on error, but in order to do better
here we would need something like `Value::Table` that tracks columns on
empty tables.
If other people disagree with this logic, I'm happy to split out the
`sort-by` and `uniq-by` changes into another PR.
# User-Facing Changes
`sort`, `uniq`, `sort-by`, and `uniq-by` now return `[]` instead of
throwing an error when input is `[]`.
# After Submitting
> If your PR had any user-facing changes, update [the
documentation](https://github.com/nushell/nushell.github.io) after the
PR is merged, if necessary. This will help us keep the docs up to date.
The existing behavior was not documented, and the new behavior is what
you would expect by default, so I don't think we need to update
documentation.
---------
Co-authored-by: Reilly Wood <reilly.wood@icloud.com>
Continuation of #8229 and #8326
# Description
The `ShellError` enum at the moment is kind of messy.
Many variants are basic tuple structs where you always have to reference
the implementation with its macro invocation to know which field serves
which purpose.
Furthermore we have both variants that are kind of redundant or either
overly broad to be useful for the user to match on or overly specific
with few uses.
So I set out to start fixing the lacking documentation and naming to
make it feasible to critically review the individual usages and fix
those.
Furthermore we can decide to join or split up variants that don't seem
to be fit for purpose.
# Call to action
**Everyone:** Feel free to add review comments if you spot inconsistent
use of `ShellError` variants.
# User-Facing Changes
(None now, end goal more explicit and consistent error messages)
# Tests + Formatting
(No additional tests needed so far)
# Commits (so far)
- Remove `ShellError::FeatureNotEnabled`
- Name fields on `SE::ExternalNotSupported`
- Name field on `SE::InvalidProbability`
- Name fields on `SE::NushellFailed` variants
- Remove unused `SE::NushellFailedSpannedHelp`
- Name field on `SE::VariableNotFoundAtRuntime`
- Name fields on `SE::EnvVarNotFoundAtRuntime`
- Name fields on `SE::ModuleNotFoundAtRuntime`
- Remove usused `ModuleOrOverlayNotFoundAtRuntime`
- Name fields on `SE::OverlayNotFoundAtRuntime`
- Name field on `SE::NotFound`
# Description
Inspired by #7592
For brevity use `Value::test_{string,int,float,bool}`
Includes fixes to commands that were abusing `Span::test_data` in their
implementation. Now the call span is used where possible or the explicit
`Span::unknonw` is used.
## Command fixes
- Fix abuse of `Span::test_data()` in `query_xml`
- Fix abuse of `Span::test_data()` in `term size`
- Fix abuse of `Span::test_data()` in `seq date`
- Fix two abuses of `Span::test_data` in `nu-cli`
- Change `Span::test_data` to `Span::unknown` in `keybindings listen`
- Add proper call span to `registry query`
- Fix span use in `nu_plugin_query`
- Fix span assignment in `select`
- Use `Span::unknown` instead of `test_data` in more places
## Other
- Use `Value::test_int`/`test_float()` consistently
- More `test_string` and `test_bool`
- Fix unused imports
# User-Facing Changes
Some commands may now provide more helpful spans for downstream use in
errors
# Description
BEFORE:
```
〉ls | size
Error: nu:🐚:pipeline_mismatch (link)
× Pipeline mismatch.
╭─[entry #22:1:1]
1 │ ls | size
· ──┬─
· │╰── value originates from here
· ╰── expected: string
╰────
〉ls | sort-by SIZE
Error: nu:🐚:column_not_found (link)
× Cannot find column
╭─[entry #17:1:1]
1 │ ls | sort-by SIZE
· ───┬───
· │╰── value originates here
· ╰── cannot find column
╰────
〉[4kb] | path join 'b'
Error: nu:🐚:pipeline_mismatch (link)
× Pipeline mismatch.
╭─[entry #6:1:1]
1 │ [4kb] | path join 'b'
· ──┬──
· │╰── value originates from here
· ╰── expected: string or record
╰────
```
AFTER:
```
〉ls | size
Error: nu:🐚:pipeline_mismatch (link)
× Pipeline mismatch.
╭─[entry #1:1:1]
1 │ ls | size
· ─┬ ──┬─
· │ ╰── expected: string
· ╰── value originates from here
╰────
〉ls | get 0 | sort-by SIZE
Error: nu:🐚:column_not_found (link)
× Cannot find column
╭─[entry #2:1:1]
1 │ ls | get 0 | sort-by SIZE
· ─┬ ───┬───
· │ ╰── cannot find column 'SIZE'
· ╰── value originates here
╰────
〉[4kb] | path join 'b'
Error: nu:🐚:pipeline_mismatch (link)
× Pipeline mismatch.
╭─[entry #1:1:1]
1 │ [4kb] | path join 'b'
· ──┬── ────┬────
· │ ╰── expected: string or record
· ╰── value originates from here
╰────
```
(Hey, anyone noticed that there's TWO wordings of "value originates from
here" in this codebase………?)
# User-Facing Changes
See above.
# Tests + Formatting
Don't forget to add tests that cover your changes.
Make sure you've run and fixed any issues with these commands:
- `cargo fmt --all -- --check` to check standard code formatting (`cargo
fmt --all` applies these changes)
- `cargo clippy --workspace --features=extra -- -D warnings -D
clippy::unwrap_used -A clippy::needless_collect` to check that you're
using the standard code style
- `cargo test --workspace --features=extra` to check that all tests pass
# After Submitting
If your PR had any user-facing changes, update [the
documentation](https://github.com/nushell/nushell.github.io) after the
PR is merged, if necessary. This will help us keep the docs up to date.
