nushell/crates/nu-command/tests/commands/select.rs
Reilly Wood 21b84a6d65
Optional members in cell paths: Attempt 2 (#8379)
This is a follow up from https://github.com/nushell/nushell/pull/7540.
Please provide feedback if you have the time!

## Summary

This PR lets you use `?` to indicate that a member in a cell path is
optional and Nushell should return `null` if that member cannot be
accessed.

Unlike the previous PR, `?` is now a _postfix_ modifier for cell path
members. A cell path of `.foo?.bar` means that `foo` is optional and
`bar` is not.

`?` does _not_ suppress all errors; it is intended to help in situations
where data has "holes", i.e. the data types are correct but something is
missing. Type mismatches (like trying to do a string path access on a
date) will still fail.

### Record Examples

```bash

{ foo: 123 }.foo # returns 123

{ foo: 123 }.bar # errors
{ foo: 123 }.bar? # returns null

{ foo: 123 } | get bar # errors
{ foo: 123 } | get bar? # returns null

{ foo: 123 }.bar.baz # errors
{ foo: 123 }.bar?.baz # errors because `baz` is not present on the result from `bar?`
{ foo: 123 }.bar.baz? # errors
{ foo: 123 }.bar?.baz? # returns null
```

### List Examples
```
〉[{foo: 1} {foo: 2} {}].foo
Error: nu:🐚:column_not_found

  × Cannot find column
   ╭─[entry #30:1:1]
 1 │ [{foo: 1} {foo: 2} {}].foo
   ·                    ─┬  ─┬─
   ·                     │   ╰── cannot find column 'foo'
   ·                     ╰── value originates here
   ╰────
〉[{foo: 1} {foo: 2} {}].foo?
╭───┬───╮
│ 0 │ 1 │
│ 1 │ 2 │
│ 2 │   │
╰───┴───╯
〉[{foo: 1} {foo: 2} {}].foo?.2 | describe
nothing

〉[a b c].4? | describe
nothing

〉[{foo: 1} {foo: 2} {}] | where foo? == 1
╭───┬─────╮
│ # │ foo │
├───┼─────┤
│ 0 │   1 │
╰───┴─────╯
```

# Breaking changes

1. Column names with `?` in them now need to be quoted.
2. The `-i`/`--ignore-errors` flag has been removed from `get` and
`select`
1. After this PR, most `get` error handling can be done with `?` and/or
`try`/`catch`.
4. Cell path accesses like this no longer work without a `?`:
```bash
〉[{a:1 b:2} {a:3}].b.0
2
```
We had some clever code that was able to recognize that since we only
want row `0`, it's OK if other rows are missing column `b`. I removed
that because it's tricky to maintain, and now that query needs to be
written like:


```bash
〉[{a:1 b:2} {a:3}].b?.0
2
```

I think the regression is acceptable for now. I plan to do more work in
the future to enable streaming of cell path accesses, and when that
happens I'll be able to make `.b.0` work again.
2023-03-15 20:50:58 -07:00

259 lines
6.2 KiB
Rust

use nu_test_support::fs::Stub::{EmptyFile, FileWithContentToBeTrimmed};
use nu_test_support::playground::Playground;
use nu_test_support::{nu, pipeline};
#[test]
fn regular_columns() {
let actual = nu!(cwd: ".", pipeline(
r#"
echo [
[first_name, last_name, rusty_at, type];
[Andrés Robalino 10/11/2013 A]
[JT Turner 10/12/2013 B]
[Yehuda Katz 10/11/2013 A]
]
| select rusty_at last_name
| get 0
| get last_name
"#
));
assert_eq!(actual.out, "Robalino");
}
#[test]
fn complex_nested_columns() {
Playground::setup("select_test_2", |dirs, sandbox| {
sandbox.with_files(vec![FileWithContentToBeTrimmed(
"los_tres_caballeros.json",
r#"
{
"nu": {
"committers": [
{"name": "Andrés N. Robalino"},
{"name": "JT Turner"},
{"name": "Yehuda Katz"}
],
"releases": [
{"version": "0.2"}
{"version": "0.8"},
{"version": "0.9999999"}
],
"0xATYKARNU": [
["Th", "e", " "],
["BIG", " ", "UnO"],
["punto", "cero"]
]
}
}
"#,
)]);
let actual = nu!(
cwd: dirs.test(), pipeline(
r#"
open los_tres_caballeros.json
| select nu."0xATYKARNU" nu.committers.name nu.releases.version
| get nu_releases_version
| where $it > "0.8"
| get 0
"#
));
assert_eq!(actual.out, "0.9999999");
})
}
#[test]
fn fails_if_given_unknown_column_name() {
let actual = nu!(cwd: ".", pipeline(
r#"
echo [
[first_name, last_name, rusty_at, type];
[Andrés Robalino 10/11/2013 A]
[JT Turner 10/12/2013 B]
[Yehuda Katz 10/11/2013 A]
]
| select rrusty_at first_name
| length
"#
));
assert!(actual.err.contains("nu::shell::name_not_found"));
}
#[test]
fn column_names_with_spaces() {
let actual = nu!(cwd: ".", pipeline(
r#"
echo [
["first name", "last name"];
[Andrés Robalino]
[Andrés Jnth]
]
| select "last name"
| get "last name"
| str join " "
"#
));
assert_eq!(actual.out, "Robalino Jnth");
}
#[test]
fn ignores_duplicate_columns_selected() {
let actual = nu!(cwd: ".", pipeline(
r#"
echo [
["first name", "last name"];
[Andrés Robalino]
[Andrés Jnth]
]
| select "first name" "last name" "first name"
| columns
| str join " "
"#
));
assert_eq!(actual.out, "first name last name");
}
#[test]
fn selects_a_row() {
Playground::setup("select_test_1", |dirs, sandbox| {
sandbox.with_files(vec![EmptyFile("notes.txt"), EmptyFile("arepas.txt")]);
let actual = nu!(
cwd: dirs.test(), pipeline(
r#"
ls
| sort-by name
| select 0
| get name.0
"#
));
assert_eq!(actual.out, "arepas.txt");
});
}
#[test]
fn selects_many_rows() {
Playground::setup("select_test_2", |dirs, sandbox| {
sandbox.with_files(vec![EmptyFile("notes.txt"), EmptyFile("arepas.txt")]);
let actual = nu!(
cwd: dirs.test(), pipeline(
r#"
ls
| get name
| select 1 0
| length
"#
));
assert_eq!(actual.out, "2");
});
}
#[test]
fn select_ignores_errors_successfully1() {
let actual = nu!(
cwd: ".", pipeline(
r#"
[{a: 1, b: 2} {a: 3, b: 5} {a: 3}] | select b? | length
"#
));
assert_eq!(actual.out, "3".to_string());
assert!(actual.err.is_empty());
}
#[test]
fn select_ignores_errors_successfully2() {
let actual = nu!(
cwd: ".", pipeline(
r#"
[{a: 1} {a: 2} {a: 3}] | select b? | to nuon
"#
));
assert_eq!(actual.out, "[[b]; [null], [null], [null]]".to_string());
assert!(actual.err.is_empty());
}
#[test]
fn select_ignores_errors_successfully3() {
let actual = nu!(
cwd: ".", pipeline(
r#"sys | select invalid_key? | to nuon"#
));
assert_eq!(actual.out, "{invalid_key: null}".to_string());
assert!(actual.err.is_empty());
}
#[test]
fn select_ignores_errors_successfully4() {
let actual = nu!(
cwd: ".", pipeline(
r#""key val\na 1\nb 2\n" | lines | split column -c " " | select foo? | to nuon"#
));
assert_eq!(actual.out, r#"[[foo]; [null], [null], [null]]"#.to_string());
assert!(actual.err.is_empty());
}
#[test]
fn select_failed1() {
let actual = nu!(
cwd: ".", pipeline(
r#"
[{a: 1, b: 2} {a: 3, b: 5} {a: 3}] | select b
"#
));
assert!(actual.out.is_empty());
assert!(actual.err.contains("cannot find column"));
}
#[test]
fn select_failed2() {
let actual = nu!(
cwd: ".", pipeline(
r#"
[{a: 1} {a: 2} {a: 3}] | select b
"#
));
assert!(actual.out.is_empty());
assert!(actual.err.contains("cannot find column"));
}
#[test]
fn select_failed3() {
let actual = nu!(
cwd: ".", pipeline(
r#""key val\na 1\nb 2\n" | lines | split column -c " " | select "100""#
));
assert!(actual.out.is_empty());
assert!(actual.err.contains("cannot find column"));
}
#[test]
fn select_failed4() {
let actual = nu!(
cwd: ".", pipeline(
r#"
[{a: 1 b: 10}, {a:2, b:11}] | select 0 0
"#
));
assert!(actual.err.contains("Select can't get the same row twice"));
}