nushell/crates/nu-command/tests/commands/slice.rs

use nu_test_support::fs::Stub::EmptyFile;
use nu_test_support::playground::Playground;
use nu_test_support::{nu, pipeline};

#[test]
fn selects_a_row() {
    Playground::setup("slice_test_1", |dirs, sandbox| {
        sandbox.with_files(&[EmptyFile("notes.txt"), EmptyFile("tests.txt")]);

        let actual = nu!(
            cwd: dirs.test(), pipeline(
            "
                ls
                | sort-by name
                | slice 0..0
                | get name.0
            "
        ));

        assert_eq!(actual.out, "notes.txt");
    });
}

#[test]
fn selects_some_rows() {
    Playground::setup("slice_test_2", |dirs, sandbox| {
        sandbox.with_files(&[
            EmptyFile("notes.txt"),
            EmptyFile("tests.txt"),
            EmptyFile("persons.txt"),
        ]);

        let actual = nu!(
            cwd: dirs.test(), pipeline(
            "
                ls
                | get name
                | slice 1..2
                | length
            "
        ));

        assert_eq!(actual.out, "2");
    });
}

#[test]
fn negative_indices() {
    Playground::setup("slice_test_negative_indices", |dirs, sandbox| {
        sandbox.with_files(&[
            EmptyFile("notes.txt"),
            EmptyFile("tests.txt"),
            EmptyFile("persons.txt"),
        ]);

        let actual = nu!(
            cwd: dirs.test(), pipeline(
            "
                ls
                | get name
                | slice (-1..)
                | length
            "
        ));

        assert_eq!(actual.out, "1");
    });
}