nushell/crates/nu-command/tests/commands/tee.rs
Devyn Cairns e69a02d379
Add tee command for operating on copies of streams (#11928)
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# Description
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This is inspired by the Unix tee command, but significantly more
powerful. Rather than just writing to a file, you can do any kind of
stream operation that Nushell supports within the closure.

The equivalent of Unix `tee -a file.txt` would be, for example, `command
| tee { save -a file.txt }` - but of course this is Nushell, and you can
do the same with structured data to JSON objects, or even just run any
other command on the system with it.

A `--stderr` flag is provided for operating on the stderr stream from
external programs. This may produce unexpected results if the stderr
stream is not then also printed by something else - nushell currently
doesn't. See #11929 for the fix for that.

# User-Facing Changes
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If someone was using the system `tee` command, they might be surprised
to find that it's different.

# Tests + Formatting
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- 🟢 `toolkit clippy`
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- 🟢 `toolkit test stdlib`


# After Submitting
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2024-02-28 17:08:31 -06:00

49 lines
1.5 KiB
Rust

use nu_test_support::{fs::file_contents, nu, playground::Playground};
#[test]
fn tee_save_values_to_file() {
Playground::setup("tee_save_values_to_file_test", |dirs, _sandbox| {
let output = nu!(
cwd: dirs.test(),
r#"1..5 | tee { save copy.txt } | to text"#
);
assert_eq!("12345", output.out);
assert_eq!(
"1\n2\n3\n4\n5\n",
file_contents(dirs.test().join("copy.txt"))
);
})
}
#[test]
fn tee_save_stdout_to_file() {
Playground::setup("tee_save_stdout_to_file_test", |dirs, _sandbox| {
let output = nu!(
cwd: dirs.test(),
r#"
$env.FOO = "teststring"
nu --testbin echo_env FOO | tee { save copy.txt }
"#
);
assert_eq!("teststring", output.out);
assert_eq!("teststring\n", file_contents(dirs.test().join("copy.txt")));
})
}
#[test]
fn tee_save_stderr_to_file() {
Playground::setup("tee_save_stderr_to_file_test", |dirs, _sandbox| {
let output = nu!(
cwd: dirs.test(),
"\
$env.FOO = \"teststring\"; \
do { nu --testbin echo_env_stderr FOO } | \
tee --stderr { save copy.txt } | \
complete | \
get stderr
"
);
assert_eq!("teststring", output.out);
assert_eq!("teststring\n", file_contents(dirs.test().join("copy.txt")));
})
}