tvl-depot/tvix/eval/tests/nix_oracle.rs
Griffin Smith e720545e5b refactor(tvix/eval): use Clap for arg+env parsing
Refactor the environment variable and argument parsing for the tvix repl
to use Clap instead of doing things ad-hoc, and thread through options
obtained from environment variables via explicit arguments rather than
obtaining them from the environment as they're needed. This makes adding
more flags more sustainable, and also makes the binary fully
self-documenting, including supported env vars, via `--help`.

Change-Id: Ib1f6a0cd20056e8c9196760ff755fa5729667760
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6653
Autosubmit: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
2022-09-18 22:08:43 +00:00

69 lines
1.9 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", "-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]");
}