nushell/crates/nu-command/tests/commands/where_.rs
Reilly Wood d409171ba8
Change comparison operators to allow nulls (#8617)
Prior to this PR, the less/greater than operators (`<`, `>`, `<=`, `>=`)
would throw an error if either side was null. After this PR, these
operators return null if either side (or both) is null.

### Examples
```bash 
1 < 3       # true
1 < null    # null
null < 3    # null
null < null # null
```

### Motivation

JT [asked the C#
folks](https://discord.com/channels/601130461678272522/615329862395101194/1086137515053957140)
and this is apparently the approach they would choose for comparison
operators if they could start from scratch.

This PR makes `where` more convenient to use on jagged/missing data. For
example, we can now filter on columns that may not be present in every
row:
```
> [{foo: 123} {}] | where foo? > 10
╭───┬─────╮
│ # │ foo │
├───┼─────┤
│ 0 │ 123 │
╰───┴─────╯
```
2023-03-26 12:10:09 +13:00

203 lines
4.4 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"));
}
// Test that filtering on columns that might be missing/null works
#[test]
fn where_gt_null() {
let actual = nu!("[{foo: 123} {}] | where foo? > 10 | to nuon");
assert_eq!(actual.out, "[[foo]; [123]]");
}