amont 1.63.0

//! `amont init` — the verb a package manager calls.
//!
//! `"prepare": "amont init"` in a `package.json` means the hooks arrive with a
//! `npm install`, so these run it the way npm would: unattended, with no
//! terminal to answer a prompt, in whatever directory the install happened in.
//!
//! Every case here is one where `install` would have done the wrong thing —
//! written outside the repository, hung on `/dev/tty`, or failed an install
//! that had no business failing.
//!
//! The journey itself (silent outside a repository, the six shims, nothing
//! outside the repository, a real commit, a re-bake, a linked worktree) is
//! `flows::onboarding`'s `the_init_journey`; the refusals and the push
//! snapshot stand-down stay here, each on a fixture of its own.

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

struct Sandbox(PathBuf);

impl Sandbox {
    fn new(name: &str) -> Self {
        let d = std::env::temp_dir().join(format!("amont-init-{name}-{}", std::process::id()));
        let _ = std::fs::remove_dir_all(&d);
        std::fs::create_dir_all(&d).expect("mkdir");
        Sandbox(d)
    }
    fn path(&self, rel: &str) -> PathBuf {
        rel.split('/').fold(self.0.clone(), |p, c| p.join(c))
    }
    /// `init`, with HOME and XDG pointed inside the sandbox so a regression that
    /// reached for either is visible as a written file rather than as damage to
    /// the developer's real configuration.
    ///
    /// **stdin is closed.** npm's `prepare` inherits a terminal, and the whole
    /// reason `init` exists rather than `install` is that `install` opens
    /// `/dev/tty` and blocks. A test that left stdin attached would pass while
    /// the real thing hung.
    fn init(&self, cwd: &Path) -> (i32, String) {
        let out = Command::new(env!("CARGO_BIN_EXE_amont"))
            .arg("init")
            .current_dir(cwd)
            .env("HOME", &self.0)
            .env("USERPROFILE", &self.0)
            .env("XDG_CONFIG_HOME", self.path(".config"))
            .stdin(std::process::Stdio::null())
            .output()
            .expect("run amont init");
        (
            out.status.code().unwrap_or(-1),
            format!(
                "{}{}",
                String::from_utf8_lossy(&out.stdout),
                String::from_utf8_lossy(&out.stderr)
            ),
        )
    }
}

impl Drop for Sandbox {
    fn drop(&mut self) {
        let _ = std::fs::remove_dir_all(&self.0);
    }
}

fn git(dir: &Path, args: &[&str]) {
    Command::new("git")
        .arg("-C")
        .arg(dir)
        .args(args)
        .output()
        .expect("git");
}

fn init_repo(dir: &Path) {
    std::fs::create_dir_all(dir).expect("mkdir");
    git(dir, &["init", "-q", "--template=", "."]);
    git(dir, &["config", "user.email", "t@t.test"]);
    git(dir, &["config", "user.name", "t"]);
}

/// `init`'s silence outside a repository is git's VERDICT ("not a git repository"), never git's
/// absence. A repository git refuses to answer about — dubious ownership in a
/// container bind mount, an unreadable `.git/config` — used to take the same
/// silent exit 0, so `npm install` logged success, the team believed hooks
/// were wired, and commits from that environment ran no checks. The doc
/// promises init "stays LOUD about everything else"; this is the everything
/// else.
#[cfg(unix)]
#[test]
fn init_is_loud_when_git_refuses_to_answer() {
    use std::os::unix::fs::PermissionsExt;
    let s = Sandbox::new("gitrefuses");
    let repo = s.path("repo");
    init_repo(&repo);
    // An unreadable `.git/config` makes every git command fail with something
    // other than "not a git repository" — the same failure class as dubious
    // ownership, which needs a second uid to stage. Skip under root, where
    // chmod 000 stops nothing.
    let config = repo.join(".git/config");
    std::fs::set_permissions(&config, std::fs::Permissions::from_mode(0o000)).expect("chmod");
    if std::fs::read(&config).is_ok() {
        return; // running as root; the fixture cannot fail
    }

    let (code, out) = s.init(&repo);
    std::fs::set_permissions(&config, std::fs::Permissions::from_mode(0o644)).expect("chmod back");
    assert_ne!(
        code, 0,
        "a repository git cannot answer about must fail init, not silently skip it:\n{out}"
    );
    assert!(
        out.contains("git would not say"),
        "the failure must say git is the blocker:\n{out}"
    );
    assert!(
        !repo.join(".git/hooks/pre-commit").exists(),
        "no shim may be written on a guess"
    );
}

/// The husky collision, from the `prepare` side.
///
/// This is the state a repository is in DURING a migration: husky still owns
/// `core.hooksPath`, and `package.json` already says `amont init`. Writing
/// either directory would be wrong — `.git/hooks` is not dispatched from, and
/// `.husky/_` is regenerated by husky's own prepare — so it fails loudly, which
/// is what makes the half-finished migration visible instead of silent.
#[test]
fn init_refuses_a_repository_husky_still_owns() {
    let s = Sandbox::new("husky");
    let repo = s.path("repo");
    init_repo(&repo);
    std::fs::create_dir_all(repo.join(".husky/_")).expect("mkdir");
    git(&repo, &["config", "core.hooksPath", ".husky/_"]);

    let (code, out) = s.init(&repo);
    assert_ne!(code, 0, "init wrote into a husky repository:\n{out}");
    assert!(out.contains("husky"), "must name the tool:\n{out}");
    assert!(
        out.contains("git config --unset core.hooksPath"),
        "must name the remedy:\n{out}"
    );
    assert!(
        !repo.join(".git/hooks/pre-commit").exists(),
        "wrote a shim git would never dispatch"
    );
    assert!(
        !repo.join(".husky/_/pre-commit").exists(),
        "wrote into the directory husky regenerates"
    );
}

/// A hook somebody wrote themselves is theirs. `init` has no `--force` and must
/// not behave as though it did: it runs unattended, so there is nobody who
/// could have decided that file was replaceable.
#[test]
fn init_refuses_to_overwrite_a_hook_it_did_not_write() {
    let s = Sandbox::new("foreign");
    let repo = s.path("repo");
    init_repo(&repo);
    let hooks = repo.join(".git/hooks");
    std::fs::create_dir_all(&hooks).expect("mkdir");
    let mine = "#!/bin/sh\n# mine, thanks\nexit 0\n";
    std::fs::write(hooks.join("pre-commit"), mine).expect("write");

    let (code, out) = s.init(&repo);
    assert_ne!(code, 0, "init overwrote a foreign hook:\n{out}");
    assert_eq!(
        std::fs::read_to_string(hooks.join("pre-commit")).expect("read"),
        mine,
        "somebody's own pre-commit was replaced"
    );
    // Fail closed for the whole repository: three shims plus one refusal is the
    // state where half the checks run and nothing says so.
    for name in ["commit-msg", "pre-push", "prepare-commit-msg"] {
        assert!(
            !hooks.join(name).exists(),
            "{name} was written despite the refusal — a half-installed repo"
        );
    }
}

// ----------------------------------------------------- push snapshots

/// A linked worktree marked the way amont's push snapshot marks itself: an
/// `amont-snapshot` file in its OWN git admin dir.
fn marked_worktree(repo: &Path, wt: &Path) {
    git(repo, &["commit", "--allow-empty", "-qm", "seed"]);
    let out = Command::new("git")
        .arg("-C")
        .arg(repo)
        .args(["worktree", "add", "-q", "--detach"])
        .arg(wt)
        .output()
        .expect("git worktree add");
    assert!(out.status.success(), "worktree add failed");
    let marker = Command::new("git")
        .arg("-C")
        .arg(wt)
        .args([
            "rev-parse",
            "--path-format=absolute",
            "--git-path",
            "amont-snapshot",
        ])
        .output()
        .expect("git rev-parse");
    let marker = PathBuf::from(String::from_utf8_lossy(&marker.stdout).trim());
    assert!(
        marker.ends_with(
            Path::new(".git/worktrees")
                .join(wt.file_name().unwrap())
                .join("amont-snapshot")
        ),
        "the marker must be worktree-private: {}",
        marker.display()
    );
    std::fs::write(marker, "").expect("mark");
}

/// Every hook file's bytes, by name, so "untouched" means byte for byte.
fn hook_bytes(dir: &Path) -> Vec<(String, Vec<u8>)> {
    let Ok(rd) = std::fs::read_dir(dir) else {
        return Vec::new();
    };
    let mut v: Vec<_> = rd
        .filter_map(|e| e.ok())
        .map(|e| {
            (
                e.file_name().to_string_lossy().into_owned(),
                std::fs::read(e.path()).unwrap_or_default(),
            )
        })
        .collect();
    v.sort();
    v
}

/// Inside a push snapshot, `init` writes nothing. The shims are baked to a
/// sentinel A first and the running binary is a different path B, so a
/// re-bake would SHOW — "unchanged" cannot pass by baking the same bytes.
#[test]
fn init_in_a_marked_snapshot_leaves_the_shared_hooks_alone() {
    let s = Sandbox::new("snapshot");
    let repo = s.path("repo");
    init_repo(&repo);
    // The worktree first: its seed commit must not run shims that point at
    // a sentinel.
    let wt = s.path("snap");
    marked_worktree(&repo, &wt);
    let (code, out) = s.init(&repo);
    assert_eq!(code, 0, "{out}");
    let hooks = repo.join(".git/hooks");
    for (name, bytes) in hook_bytes(&hooks) {
        let text = String::from_utf8_lossy(&bytes)
            .replace(env!("CARGO_BIN_EXE_amont"), "/sentinel/A/amont");
        std::fs::write(hooks.join(name), text).expect("seed");
    }
    let before = hook_bytes(&hooks);
    let shims: Vec<_> = before
        .iter()
        .filter(|(_, b)| String::from_utf8_lossy(b).contains("BAKED="))
        .collect();
    assert!(!shims.is_empty(), "no amont shims to seed");
    assert!(
        shims
            .iter()
            .all(|(_, b)| String::from_utf8_lossy(b).contains("/sentinel/A/amont")),
        "the sentinel did not take: a re-bake could not show"
    );

    let (code, out) = s.init(&wt);
    assert_eq!(code, 0, "{out}");
    assert!(out.contains("inside an amont push snapshot"), "{out}");
    assert_eq!(before, hook_bytes(&hooks), "init re-baked from a snapshot");
}

/// The stand-down comes BEFORE hook config is judged: a redirect `init`
/// would refuse anywhere else must not fail a snapshot's `prepare`, since
/// nothing is going to be written either way.
#[test]
fn init_in_a_marked_snapshot_does_not_fail_over_a_redirect() {
    let s = Sandbox::new("snapshot-husky");
    let repo = s.path("repo");
    init_repo(&repo);
    std::fs::create_dir_all(repo.join(".husky/_")).expect("mkdir");
    git(&repo, &["config", "core.hooksPath", ".husky/_"]);
    let wt = s.path("snap");
    marked_worktree(&repo, &wt);

    let (code, out) = s.init(&wt);
    assert_eq!(code, 0, "{out}");
    assert!(hook_bytes(&repo.join(".git/hooks")).is_empty(), "{out}");
    assert!(hook_bytes(&repo.join(".husky/_")).is_empty(), "{out}");
    // …and outside the snapshot it is still refused, as before.
    let (code, out) = s.init(&repo);
    assert_ne!(code, 0, "{out}");
}

/// Why a marker in the snapshot's git dir and not an inherited variable:
/// while a snapshot exists, `init` in ANOTHER repository — with
/// `AMONT_SNAPSHOT=1` in its environment, as a suite run from a snapshot
/// would inherit — still bakes that repository's hooks normally.
#[test]
fn a_snapshot_elsewhere_does_not_stop_init_in_another_repository() {
    let s = Sandbox::new("isolation");
    let repo = s.path("repo");
    init_repo(&repo);
    let wt = s.path("snap");
    marked_worktree(&repo, &wt);
    let other = s.path("other");
    init_repo(&other);

    let out = Command::new(env!("CARGO_BIN_EXE_amont"))
        .arg("init")
        .current_dir(&other)
        .env("HOME", s.path(""))
        .env("XDG_CONFIG_HOME", s.path(".config"))
        .env("AMONT_SNAPSHOT", "1")
        .stdin(std::process::Stdio::null())
        .output()
        .expect("run amont init");
    let text = format!(
        "{}{}",
        String::from_utf8_lossy(&out.stdout),
        String::from_utf8_lossy(&out.stderr)
    );
    assert!(out.status.success(), "{text}");
    assert!(!text.contains("inside an amont push snapshot"), "{text}");
    let hook = std::fs::read_to_string(other.join(".git/hooks/pre-commit")).expect("baked");
    assert!(hook.contains(env!("CARGO_BIN_EXE_amont")), "{hook}");
}