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

196 lines
4.2 KiB
Rust

use nu_test_support::nu;
use nu_test_support::pipeline;
#[test]
fn filters_by_unit_size_comparison() {
let actual = nu!(
cwd: "tests/fixtures/formats",
"ls | where size > 1kib | sort-by size | get name | first | str trim"
);
assert_eq!(actual.out, "cargo_sample.toml");
}
#[test]
fn filters_with_nothing_comparison() {
let actual = nu!(
cwd: "tests/fixtures/formats",
r#"'[{"foo": 3}, {"foo": null}, {"foo": 4}]' | from json | get foo | compact | where $it > 1 | math sum"#
);
assert_eq!(actual.out, "7");
}
#[test]
fn where_inside_block_works() {
let actual = nu!(
cwd: ".",
"{|x| ls | where $it =~ 'foo' } | describe"
);
assert_eq!(actual.out, "closure");
}
#[test]
fn filters_with_0_arity_block() {
let actual = nu!(
cwd: ".",
"[1 2 3 4] | where { $in < 3 } | to nuon"
);
assert_eq!(actual.out, "[1, 2]");
}
#[test]
fn filters_with_1_arity_block() {
let actual = nu!(
cwd: ".",
"[1 2 3 6 7 8] | where {|e| $e < 5 } | to nuon"
);
assert_eq!(actual.out, "[1, 2, 3]");
}
#[test]
fn unique_env_each_iteration() {
let actual = nu!(
cwd: "tests/fixtures/formats",
"[1 2] | where { print ($env.PWD | str ends-with 'formats') | cd '/' | true } | to nuon"
);
assert_eq!(actual.out, "truetrue[1, 2]");
}
#[test]
fn where_in_table() {
let actual = nu!(
cwd: "tests/fixtures/formats",
r#"'[{"name": "foo", "size": 3}, {"name": "foo", "size": 2}, {"name": "bar", "size": 4}]' | from json | where name in ["foo"] | get size | math sum"#
);
assert_eq!(actual.out, "5");
}
#[test]
fn where_not_in_table() {
let actual = nu!(
cwd: "tests/fixtures/formats",
r#"'[{"name": "foo", "size": 3}, {"name": "foo", "size": 2}, {"name": "bar", "size": 4}]' | from json | where name not-in ["foo"] | get size | math sum"#
);
assert_eq!(actual.out, "4");
}
#[test]
fn where_uses_enumerate_index() {
let actual = nu!(
cwd: ".",
r#"[7 8 9 10] | enumerate | where {|el| $el.index < 2 } | to nuon"#
);
assert_eq!(actual.out, "[[index, item]; [0, 7], [1, 8]]");
}
#[cfg(feature = "sqlite")]
#[test]
fn binary_operator_comparisons() {
let actual = nu!(
cwd: "tests/fixtures/formats", pipeline(
r#"
open sample.db
| get ints
| first 4
| where z > 4200
| get z.0
"#
));
assert_eq!(actual.out, "4253");
let actual = nu!(
cwd: "tests/fixtures/formats", pipeline(
r#"
open sample.db
| get ints
| first 4
| where z >= 4253
| get z.0
"#
));
assert_eq!(actual.out, "4253");
let actual = nu!(
cwd: "tests/fixtures/formats", pipeline(
r#"
open sample.db
| get ints
| first 4
| where z < 10
| get z.0
"#
));
assert_eq!(actual.out, "1");
let actual = nu!(
cwd: "tests/fixtures/formats", pipeline(
r#"
open sample.db
| get ints
| first 4
| where z <= 1
| get z.0
"#
));
assert_eq!(actual.out, "1");
let actual = nu!(
cwd: "tests/fixtures/formats", pipeline(
r#"
open sample.db
| get ints
| where z != 1
| first
| get z
"#
));
assert_eq!(actual.out, "42");
}
#[cfg(feature = "sqlite")]
#[test]
fn contains_operator() {
let actual = nu!(
cwd: "tests/fixtures/formats", pipeline(
r#"
open sample.db
| get strings
| where x =~ ell
| length
"#
));
assert_eq!(actual.out, "4");
let actual = nu!(
cwd: "tests/fixtures/formats", pipeline(
r#"
open sample.db
| get strings
| where x !~ ell
| length
"#
));
assert_eq!(actual.out, "2");
}
#[test]
fn fail_on_non_iterator() {
let actual = nu!(cwd: ".", pipeline(r#"{"name": "foo", "size": 3} | where name == "foo""#));
assert!(actual.err.contains("only_supports_this_input_type"));
}