nushell/crates/nu-command/tests/commands/reject.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

149 lines
3.5 KiB
Rust

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]
]
| reject type first_name
| columns
| str join ", "
"#
));
assert_eq!(actual.out, "last_name, rusty_at");
}
#[test]
fn skip_cell_rejection() {
let actual = nu!(cwd: ".", pipeline(
r#"[ {a: 1, b: 2,c:txt}, { a:val } ] | reject a | get c?.0"#));
assert_eq!(actual.out, "txt");
}
#[test]
fn complex_nested_columns() {
let actual = nu!(cwd: ".", pipeline(
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"]
]
}
}
| reject nu."0xATYKARNU" nu.committers
| get nu
| columns
| str join ", "
"#,
));
assert_eq!(actual.out, "releases");
}
#[test]
fn ignores_duplicate_columns_rejected() {
let actual = nu!(cwd: ".", pipeline(
r#"
echo [
["first name", "last name"];
[Andrés Robalino]
[Andrés Jnth]
]
| reject "first name" "first name"
| columns
| str join ", "
"#
));
assert_eq!(actual.out, "last name");
}
#[test]
fn reject_record_from_raw_eval() {
let actual = nu!(
cwd: ".", pipeline(
r#"
{"a": 3, "a": 4} | reject a | describe
"#
)
);
assert!(actual.out.contains("record"));
}
#[test]
fn reject_table_from_raw_eval() {
let actual = nu!(
cwd: ".", pipeline(
r#"
[{"a": 3, "a": 4}] | reject a
"#
)
);
assert!(actual.out.contains("record 0 fields"));
}
#[test]
fn reject_nested_field() {
let actual = nu!(
cwd: ".", pipeline(
r#"
{a:{b:3,c:5}} | reject a.b | debug
"#
)
);
assert_eq!(actual.out, "{a: {c: 5}}");
}
#[test]
fn reject_two_identical_elements() {
let actual = nu!(
cwd: ".", pipeline(
r#"[[a, a]; [1, 2]] | reject a"#
)
);
assert!(actual.out.contains("record 0 fields"));
}
#[test]
fn reject_large_vec_with_two_identical_elements() {
let actual = nu!(
cwd: ".", pipeline(
r#"[[a, b, c, d, e, a]; [1323, 23, 45, 100, 2, 2423]] | reject a"#
)
);
assert!(!actual.out.contains("1323"));
assert!(!actual.out.contains("2423"));
assert!(actual.out.contains('b'));
assert!(actual.out.contains('c'));
assert!(actual.out.contains('d'));
assert!(actual.out.contains('e'));
assert!(actual.out.contains("23"));
assert!(actual.out.contains("45"));
assert!(actual.out.contains("100"));
assert!(actual.out.contains('2'));
}