tvl-depot/tvix/eval/tests/nix_oracle.rs
Griffin Smith 0e9f5d6890 feat(tvix/eval): Allow adding strings to paths
Implement adding paths and strings via OpAdd. Since the nix rules are
quite obscure, I'm electing to test this one with an oracle test to
avoid the danger of getting the actual asserted result wrong.

Change-Id: Icdcca3690ca2e8459e386c1f29cc48eaaa39e9a3
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6914
Autosubmit: grfn <grfn@gws.fyi>
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2022-10-10 20:23:41 +00:00

78 lines
2.2 KiB
Rust

//! Tests which use upstream nix as an oracle to test evaluation against
use std::{env, path::PathBuf, process::Command};
use pretty_assertions::assert_eq;
use tempdir::TempDir;
fn nix_binary_path() -> PathBuf {
env::var("NIX_INSTANTIATE_BINARY_PATH")
.unwrap_or_else(|_| "nix-instantiate".to_owned())
.into()
}
fn nix_eval(expr: &str) -> String {
let store_dir = TempDir::new("store-dir").unwrap();
let output = Command::new(nix_binary_path())
.args(["--eval", "--strict", "-E"])
.arg(format!("({expr})"))
.env(
"NIX_REMOTE",
format!("local?root={}", store_dir.path().display()),
)
.output()
.unwrap();
if !output.status.success() {
panic!(
"nix eval {expr} failed!\n stdout: {}\n stderr: {}",
String::from_utf8_lossy(&output.stdout),
String::from_utf8_lossy(&output.stderr)
)
}
String::from_utf8(output.stdout).unwrap()
}
/// Compare the evaluation of the given nix expression in nix (using the
/// `NIX_INSTANTIATE_BINARY_PATH` env var to resolve the `nix-instantiate` binary) and tvix, and
/// assert that the result is identical
#[track_caller]
fn compare_eval(expr: &str) {
let nix_result = nix_eval(expr);
let tvix_result = tvix_eval::interpret(expr, None, Default::default())
.unwrap()
.to_string();
assert_eq!(nix_result.trim(), tvix_result);
}
/// Generate a suite of tests which call [`compare_eval`] on expressions, checking that nix and tvix
/// return identical results.
macro_rules! compare_eval_tests {
() => {};
($(#[$meta:meta])* $test_name: ident($expr: expr); $($rest:tt)*) => {
#[test]
$(#[$meta])*
fn $test_name() {
compare_eval($expr);
}
compare_eval_tests!($($rest)*);
}
}
compare_eval_tests! {
literal_int("1");
add_ints("1 + 1");
add_lists("[1 2] ++ [3 4]");
add_paths(r#"[
(./. + "/")
(./foo + "bar")
(let name = "bar"; in ./foo + name)
(let name = "bar"; in ./foo + "${name}")
(let name = "bar"; in ./foo + "/" + "${name}")
(let name = "bar"; in ./foo + "/${name}")
(./. + ./.)
]"#);
}