nordisk/holger

build-space/tests/example_press_runs.rs

//! # The worked example is actually RUN — not just compiled
//!
//! `cargo test` compiles examples but never runs their `main()`, so the flagship
//! *"a consumer presses the build-thing button"* demo
//! (`build-space/examples/press_build_thing.rs`, task #36) could silently rot
//! while the suite stayed green. This test drives the example end-to-end via
//! `cargo run --example press_build_thing` and asserts it exits 0 and prints the
//! key describe→press→ledger→reload lines — so the demo can never drift dead.

use std::process::Command;

/// Run the canonical example as a subprocess and assert it succeeds + emits the
/// milestone lines a reader relies on. LAW: inject a real run, assert the real
/// observable output (exit code + stdout), never merely "it compiled".
#[test]
fn press_build_thing_example_runs_end_to_end() {
    // Run from THIS crate's manifest dir so `--example` resolves against
    // holger-build-space regardless of the workspace CWD.
    let manifest = env!("CARGO_MANIFEST_DIR");
    let out = Command::new(env!("CARGO"))
        .args([
            "run",
            "--quiet",
            "-p",
            "holger-build-space",
            "--example",
            "press_build_thing",
        ])
        .current_dir(manifest)
        .output()
        .expect("spawn cargo run --example press_build_thing");

    let stdout = String::from_utf8_lossy(&out.stdout);
    let stderr = String::from_utf8_lossy(&out.stderr);

    // Exit 0: the example's own `assert!(digest_matches_record)` and the
    // round-trip `assert_eq!(reloaded, rec)` both held.
    assert!(
        out.status.success(),
        "example must exit 0.\n--- stdout ---\n{stdout}\n--- stderr ---\n{stderr}"
    );

    // DESCRIBE half: the products were reflected as a surface.
    assert!(
        stdout.contains("repo 'holger'"),
        "names the repo:\n{stdout}"
    );
    for row in [
        "holger-downstream",
        "holger-cli",
        "holger-ui",
        "mvp-server-musl",
    ] {
        assert!(
            stdout.contains(row),
            "surface lists the '{row}' row:\n{stdout}"
        );
    }

    // PRESS half: the `holger` row was pressed into a content-addressed record,
    // its digest printed, and it verified.
    assert!(
        stdout.contains("pressed 'holger'"),
        "reports pressing the holger row:\n{stdout}"
    );
    assert!(
        stdout.contains("digest      :"),
        "prints the digest line:\n{stdout}"
    );
    assert!(
        stdout.contains("sha256:"),
        "prints the artifact content hash:\n{stdout}"
    );

    // LEDGER half: the record persisted, reloaded, and round-tripped.
    assert!(stdout.contains("reloaded"), "reports the reload:\n{stdout}");
    assert!(
        stdout.contains("record round-trips"),
        "asserts round-trip:\n{stdout}"
    );
    assert!(stdout.contains("OK"), "ends with the OK summary:\n{stdout}");
}