nordisk/edda

crates/nornir-config/tests/pin_base.rs

//! The embedder seam, driven through the REAL process-global setter.
//!
//! `pin_nornir_base` is set-once per PROCESS, so this has to be an integration
//! test (its own binary) rather than a unit test sharing the lib's test process
//! with the `$HOME`-mutating ones. Its sibling `pin_after_read.rs` proves the
//! opposite order in a second process.

use std::path::{Path, PathBuf};

/// **The whole point.** After an embedder pins its own data root as the base,
/// EVERY nornir root hangs inside it — and `$HOME` no longer decides.
///
/// The `$HOME` half is the assertion that matters: before this seam existed the
/// only lever was `$HOME`, which also moves `~/.cargo`, `~/.rustup` and the
/// server's PATH injection. Moving `$HOME` here and watching the root NOT follow
/// is what proves the lever is gone.
///
/// RED WHEN REVERTED: make `nornir_home()` ignore `PINNED_BASE` (i.e. restore the
/// old one-line `nornir_home_from(&home::home_dir()…)`) and every assertion below
/// reports `/home/pin-test-home/.nornir…` instead of the pinned tree.
#[test]
fn a_pinned_base_owns_every_root_and_home_no_longer_moves_it() {
    // A `$HOME` that is deliberately NOT the pinned base. If anything still reads
    // it, the assertions below name this tree and fail.
    // SAFETY: single-threaded test process; nothing else has read the root yet.
    unsafe { std::env::set_var("HOME", "/home/pin-test-home") };

    assert_eq!(nornir_config::pinned_nornir_base(), None, "nothing pinned yet");

    let base = Path::new("/home/dwarves/.dwarves");
    let root = nornir_config::pin_nornir_base(base).expect("pin the declared data root");

    // The root is INSIDE the base — the property that lets the embedder delete its
    // second declared root.
    assert_eq!(root, PathBuf::from("/home/dwarves/.dwarves/.nornir"));
    assert!(root.starts_with(base), "{} is not inside {}", root.display(), base.display());
    assert_eq!(nornir_config::pinned_nornir_base().as_deref(), Some(base));

    // Every composed root follows the pin, not `$HOME`.
    assert_eq!(nornir_config::nornir_home(), PathBuf::from("/home/dwarves/.dwarves/.nornir"));
    assert_eq!(
        nornir_config::registry_root(),
        PathBuf::from("/home/dwarves/.dwarves/.nornir/workspaces"),
    );
    assert_eq!(
        nornir_config::warehouse_default_root(),
        PathBuf::from("/home/dwarves/.dwarves/.nornir/warehouse"),
    );
    // …including the per-workspace warehouse the server actually opens — the
    // 3.0 GB `nordisk/builds` tree, not just the bare root.
    let loaded = nornir_config::Loaded {
        nornir: nornir_config::Nornir::default(),
        config_path: PathBuf::from("/ws/workspace_nordisk/release/nornir.toml"),
        workspace_root: PathBuf::from("/ws"),
    };
    assert_eq!(
        loaded.warehouse_root(),
        PathBuf::from("/home/dwarves/.dwarves/.nornir/workspaces/nordisk/builds"),
    );

    // MOVE `$HOME` again. The root must not budge — that is the lever being gone.
    // SAFETY: single-threaded test process.
    unsafe { std::env::set_var("HOME", "/home/somewhere-else-entirely") };
    assert_eq!(
        nornir_config::nornir_home(),
        PathBuf::from("/home/dwarves/.dwarves/.nornir"),
        "the pinned root followed $HOME — the pin is not authoritative",
    );

    // Idempotent: the same base again is a no-op (an embedder may pin from more
    // than one entry point).
    assert_eq!(
        nornir_config::pin_nornir_base(base).expect("re-pinning the same base is a no-op"),
        root,
    );

    // A DIFFERENT base is the two-roots bug — refused, and it names both paths.
    let err = nornir_config::pin_nornir_base(Path::new("/home/dwarves/.other"))
        .expect_err("a second, different base must be refused");
    assert_eq!(
        err,
        nornir_config::PinRefused::Conflict {
            pinned: base.to_path_buf(),
            attempted: PathBuf::from("/home/dwarves/.other"),
        },
    );
    // …and the refusal did not change anything.
    assert_eq!(nornir_config::nornir_home(), PathBuf::from("/home/dwarves/.dwarves/.nornir"));
}