nordisk/Skidbladnir

tests/probe_suite.rs

//! Runs the `probe/` crate's own test suite as part of THIS crate's `cargo test`.
//!
//! # Why this file exists
//!
//! `probe/` is a deliberately standalone workspace (`probe/Cargo.toml` declares its
//! own `[workspace]`) so the probe can cross-compile to static musl without the
//! parent's ring/zbus/rcgen closure. That isolation has a cost nobody had paid:
//! **the parent's `cargo test` never reaches it, and this repo has no CI.** The
//! probe's tests therefore only ever ran if a human hand-typed
//! `--manifest-path probe/Cargo.toml`.
//!
//! That is the same failure the probe itself was just fixed for, one level up: a
//! suite that cannot fail because it is never invoked is not evidence. The probe is
//! the component the whole install matrix TRUSTS as ground truth
//! (`matrix::ProbeReport::is_healthy` → `running && health.ok`), so its tests are
//! precisely the ones that must not be optional.
//!
//! The nested crate has **zero dependencies** (std only), so this costs a sub-second
//! compile and needs no network — hence `--offline`, which also keeps a `cargo test`
//! in an airgapped guest honest.

use std::path::Path;
use std::process::Command;

#[test]
fn the_probe_crates_own_tests_pass() {
    let root = Path::new(env!("CARGO_MANIFEST_DIR"));
    let manifest = root.join("probe/Cargo.toml");
    assert!(
        manifest.exists(),
        "probe/Cargo.toml is missing — the install matrix has no ground-truth probe \
         to inject ({})",
        manifest.display()
    );

    // A private target dir: never share the parent's (different workspace, and a
    // shared dir invites fingerprint churn between the two).
    let target_dir = Path::new(env!("CARGO_TARGET_TMPDIR")).join("probe-suite");

    let out = Command::new(env!("CARGO"))
        .args(["test", "--offline", "--manifest-path"])
        .arg(&manifest)
        .arg("--target-dir")
        .arg(&target_dir)
        // Inherited CARGO_* from the outer invocation would otherwise redirect the
        // nested build back into the parent's workspace.
        .env_remove("CARGO_TARGET_DIR")
        .env_remove("CARGO_BUILD_TARGET")
        .output()
        .expect("invoke cargo for the probe crate");

    if !out.status.success() {
        panic!(
            "the probe crate's tests FAILED — the install matrix's ground truth is \
             untrustworthy until they pass.\n\
             --- stdout ---\n{}\n--- stderr ---\n{}",
            String::from_utf8_lossy(&out.stdout),
            String::from_utf8_lossy(&out.stderr),
        );
    }

    // Guard against the suite silently emptying out: `cargo test` exits 0 for a
    // crate with no tests at all, which would restore the very hole this closes.
    let stdout = String::from_utf8_lossy(&out.stdout);
    let ran: usize = stdout
        .lines()
        .filter_map(|l| l.strip_prefix("running "))
        .filter_map(|l| l.split_whitespace().next())
        .filter_map(|n| n.parse::<usize>().ok())
        .sum();
    assert!(
        ran >= 15,
        "expected the probe suite to still contain its regression tests, but only \
         {ran} test(s) ran. Did a target get renamed or a test file dropped?\n{stdout}"
    );
}