nushell/crates/nu-command/tests/commands/first.rs
Reilly Wood 95d4922e44
Make stream info visible to users in describe (#7589)
Closes #7581.

After this PR, `describe` shows `(stream)` next to input that arrived at
`describe` as a `ListStream`:
```bash
〉ls | describe
table<name: string, type: string, size: filesize, modified: date> (stream)
〉[1 2 3] | each {|i| $i} | describe
list<int> (stream)
```

`describe` must collect all items of the stream to display type
information for lists and tables. If users need to avoid collecting
input, they can use the `-n`/`--no-collect` flag:

```bash
〉[1 2 3] | each {|i| $i} | describe --no-collect
stream
```
2023-01-03 21:08:05 -08:00

108 lines
2.3 KiB
Rust

use nu_test_support::fs::Stub::EmptyFile;
use nu_test_support::playground::Playground;
use nu_test_support::{nu, pipeline};
#[test]
fn gets_first_rows_by_amount() {
Playground::setup("first_test_1", |dirs, sandbox| {
sandbox.with_files(vec![
EmptyFile("los.txt"),
EmptyFile("tres.txt"),
EmptyFile("amigos.txt"),
EmptyFile("arepas.clu"),
]);
let actual = nu!(
cwd: dirs.test(), pipeline(
r#"
ls
| first 3
| length
"#
));
assert_eq!(actual.out, "3");
})
}
#[test]
fn gets_all_rows_if_amount_higher_than_all_rows() {
Playground::setup("first_test_2", |dirs, sandbox| {
sandbox.with_files(vec![
EmptyFile("los.txt"),
EmptyFile("tres.txt"),
EmptyFile("amigos.txt"),
EmptyFile("arepas.clu"),
]);
let actual = nu!(
cwd: dirs.test(), pipeline(
r#"
ls
| first 99
| length
"#
));
assert_eq!(actual.out, "4");
})
}
#[test]
fn gets_first_row_when_no_amount_given() {
Playground::setup("first_test_3", |dirs, sandbox| {
sandbox.with_files(vec![EmptyFile("caballeros.txt"), EmptyFile("arepas.clu")]);
let actual = nu!(
cwd: dirs.test(), pipeline(
r#"
ls
| first
| length
"#
));
assert_eq!(actual.out, "1");
})
}
#[test]
fn gets_first_row_as_list_when_amount_given() {
let actual = nu!(
cwd: ".", pipeline(
r#"
[1, 2, 3]
| first 1
| describe
"#
));
assert_eq!(actual.out, "list<int> (stream)");
}
#[test]
// covers a situation where `first` used to behave strangely on list<binary> input
fn works_with_binary_list() {
let actual = nu!(
cwd: ".", pipeline(
r#"
([0x[01 11]] | first) == 0x[01 11]
"#
));
assert_eq!(actual.out, "true");
}
#[test]
fn errors_on_negative_rows() {
let actual = nu!(
cwd: ".", pipeline(
r#"
[1, 2, 3]
| first -10
"#
));
assert!(actual.err.contains("use a positive value"));
}