allow select to take a $variable with a list of columns (#9987)

# Description

This PR enables `select` to take a constructed list of columns as a
variable.

```nushell
> let cols = [name type];[[name type size]; [Cargo.toml toml 1kb] [Cargo.lock toml 2kb]] | select $cols
  ╭#┬───name───┬type╮
  │0│Cargo.toml│toml│
  │1│Cargo.lock│toml│
  ╰─┴──────────┴────╯
```
and rows
```nushell
> let rows = [0 2];[[name type size]; [Cargo.toml toml 1kb] [Cargo.lock toml 2kb] [file.json json 3kb]] | select $rows
  ╭#┬───name───┬type┬size╮
  │0│Cargo.toml│toml│1kb │
  │1│file.json │json│3kb │
  ╰─┴──────────┴────┴────╯
```

# User-Facing Changes
<!-- List of all changes that impact the user experience here. This
helps us keep track of breaking changes. -->

# 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 -- -D warnings -D clippy::unwrap_used -A
clippy::needless_collect -A clippy::result_large_err` to check that
you're using the standard code style
- `cargo test --workspace` to check that all tests pass
- `cargo run -- -c "use std testing; testing run-tests --path
crates/nu-std"` to run the tests for the standard library

> **Note**
> from `nushell` you can also use the `toolkit` as follows
> ```bash
> use toolkit.nu # or use an `env_change` hook to activate it
automatically
> toolkit check pr
> ```
-->

# 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.
-->
This commit is contained in:
Darren Schroeder
2023-08-15 07:01:45 -05:00
committed by GitHub
parent 8b160f9850
commit 3ed45c7ba8
2 changed files with 97 additions and 4 deletions

View File

@ -244,3 +244,23 @@ fn select_on_empty_list_returns_empty_list() {
let actual = nu!("[] | each {|i| $i} | select foo | to nuon");
assert_eq!(actual.out, "[]");
}
#[test]
fn select_columns_with_variable_list() {
let actual = nu!(r#"
let columns = [a c];
echo [[a b c]; [1 2 3]] | select $columns | to nuon
"#);
assert_eq!(actual.out, "[[a, c]; [1, 3]]");
}
#[test]
fn select_rows_with_variable_list() {
let actual = nu!(r#"
let rows = [0 2];
echo [[a b c]; [1 2 3] [4 5 6] [7 8 9]] | select $rows | to nuon
"#);
assert_eq!(actual.out, "[[a, b, c]; [1, 2, 3], [7, 8, 9]]");
}