sluuz 0.10.6

//! What the plain commands promise a script: a failure goes to stderr and the
//! exit code says so.

use std::fs;
use std::path::PathBuf;
use std::process::Command;
use std::time::{SystemTime, UNIX_EPOCH};

/// An empty folder under the system temp dir, deleted when it goes out of
/// scope, including when an assertion panics.
struct TempDir(PathBuf);

impl TempDir {
    fn new(tag: &str) -> TempDir {
        let stamp = SystemTime::now()
            .duration_since(UNIX_EPOCH)
            .map(|d| d.as_nanos())
            .unwrap_or(0);
        let dir = std::env::temp_dir().join(format!("sluuz-{tag}-{stamp}"));
        fs::create_dir_all(&dir).expect("temp dir");
        TempDir(dir)
    }
}

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

#[test]
fn a_scan_that_finds_no_repo_exits_non_zero() {
    let dir = TempDir::new("norepo");
    // Stops git looking above the temp dir, so a machine whose temp dir sits
    // inside a repo cannot hand the scan one.
    let ceiling = dir.0.parent().expect("temp dir has a parent");

    for cmd in ["repos", "sync", "tidy"] {
        let out = Command::new(env!("CARGO_BIN_EXE_slu"))
            .arg(cmd)
            .current_dir(&dir.0)
            .env("GIT_CEILING_DIRECTORIES", ceiling)
            .output()
            .expect("run slu");
        assert!(!out.status.success(), "`slu {cmd}` with no repo exited 0");
        assert!(
            out.stdout.is_empty(),
            "`slu {cmd}` put its failure on stdout"
        );
        assert!(
            !out.stderr.is_empty(),
            "`slu {cmd}` failed without saying why"
        );
    }
}

#[test]
fn a_reader_that_stops_early_ends_the_output_quietly() {
    let dir = TempDir::new("pipe");
    let git = |args: &[&str]| {
        let ok = Command::new("git")
            .args(args)
            .current_dir(&dir.0)
            .env("GIT_CONFIG_NOSYSTEM", "1")
            .env("GIT_CONFIG_GLOBAL", "/dev/null")
            .status()
            .expect("run git")
            .success();
        assert!(ok, "`git {}` failed", args.join(" "));
    };
    git(&["init", "-q"]);
    git(&[
        "-c",
        "user.name=Test",
        "-c",
        "user.email=test@example.com",
        "commit",
        "-q",
        "--allow-empty",
        "-m",
        "one",
    ]);

    // What `slu trace | head` does to it, every time: the read end is gone
    // before the first line is written.
    let (reader, writer) = std::io::pipe().expect("pipe");
    drop(reader);
    let out = Command::new(env!("CARGO_BIN_EXE_slu"))
        .arg("trace")
        .current_dir(&dir.0)
        .env("GIT_CONFIG_NOSYSTEM", "1")
        .env("GIT_CONFIG_GLOBAL", "/dev/null")
        .stdout(writer)
        .output()
        .expect("run slu");
    assert!(
        out.status.success(),
        "`slu trace` into a closed pipe exited {:?}",
        out.status.code()
    );
    assert!(
        out.stderr.is_empty(),
        "`slu trace` into a closed pipe complained: {}",
        String::from_utf8_lossy(&out.stderr)
    );
}

/// Runs the built `slu` in `dir` with git's own config files kept out.
fn slu(dir: &std::path::Path, args: &[&str]) -> std::process::Output {
    Command::new(env!("CARGO_BIN_EXE_slu"))
        .args(args)
        .current_dir(dir)
        .env("GIT_CONFIG_NOSYSTEM", "1")
        .env("GIT_CONFIG_GLOBAL", "/dev/null")
        .output()
        .expect("run slu")
}

#[test]
fn each_dash_c_is_relative_to_the_one_before_and_applied_once() {
    let dir = TempDir::new("dash-c");
    let repo = dir.0.join("a").join("b");
    fs::create_dir_all(&repo).expect("repo dir");
    let ok = Command::new("git")
        .args(["init", "-q"])
        .current_dir(&repo)
        .env("GIT_CONFIG_NOSYSTEM", "1")
        .env("GIT_CONFIG_GLOBAL", "/dev/null")
        .status()
        .expect("run git")
        .success();
    assert!(ok, "`git init` failed");

    let out = slu(
        &dir.0,
        &["-C", "a", "-C", "b", "rev-parse", "--show-toplevel"],
    );
    assert!(
        out.status.success(),
        "`slu -C a -C b rev-parse` failed: {}",
        String::from_utf8_lossy(&out.stderr)
    );
    let top = String::from_utf8_lossy(&out.stdout);
    assert_eq!(
        fs::canonicalize(top.trim()).expect("toplevel exists"),
        fs::canonicalize(&repo).expect("repo exists"),
        "`-C a -C b` did not land in a/b"
    );
}

#[test]
fn git_options_before_the_command_reach_git() {
    let dir = TempDir::new("git-opts");
    let out = slu(
        &dir.0,
        &[
            "--no-pager",
            "-c",
            "sluuz.probe=yes",
            "config",
            "sluuz.probe",
        ],
    );
    assert!(
        out.status.success(),
        "`slu --no-pager -c … config` failed: {}",
        String::from_utf8_lossy(&out.stderr)
    );
    assert_eq!(
        String::from_utf8_lossy(&out.stdout).trim(),
        "yes",
        "the `-c` value never reached git"
    );
}

#[cfg(unix)]
#[test]
fn sync_never_runs_more_than_eight_fetches_at_once() {
    use std::os::unix::fs::PermissionsExt;

    let dir = TempDir::new("fetches");
    let (bin, running, log, tree) = (
        dir.0.join("bin"),
        dir.0.join("running"),
        dir.0.join("log"),
        dir.0.join("tree"),
    );
    fs::create_dir_all(&bin).expect("bin dir");
    fs::create_dir_all(&running).expect("running dir");
    // A stand-in for git that notes how many fetches are in flight as it joins them.
    let fake_git = format!(
        "#!/bin/sh\n\
         case \" $* \" in *\" fetch \"*) ;; *) exit 0 ;; esac\n\
         : > '{running}/'$$\n\
         ls '{running}' | wc -l >> '{log}'\n\
         sleep 0.2\n\
         rm -f '{running}/'$$\n",
        running = running.display(),
        log = log.display(),
    );
    let git = bin.join("git");
    fs::write(&git, fake_git).expect("write the fake git");
    fs::set_permissions(&git, fs::Permissions::from_mode(0o755)).expect("make it runnable");

    const REPOS: usize = 24;
    for i in 0..REPOS {
        fs::create_dir_all(tree.join(format!("r{i}/.git"))).expect("repo dir");
    }

    let path = format!(
        "{}:{}",
        bin.display(),
        std::env::var("PATH").expect("PATH is set")
    );
    let out = Command::new(env!("CARGO_BIN_EXE_slu"))
        .arg("sync")
        .arg(&tree)
        .env("PATH", path)
        // More threads than repos, so a lost limit shows on a machine of any size.
        .env("RAYON_NUM_THREADS", "32")
        .output()
        .expect("run slu");
    assert!(
        out.status.success(),
        "`slu sync` failed: {}",
        String::from_utf8_lossy(&out.stderr)
    );

    let seen: Vec<usize> = fs::read_to_string(&log)
        .expect("the fake git was never asked to fetch")
        .lines()
        .map(|l| l.trim().parse().expect("a count"))
        .collect();
    assert_eq!(seen.len(), REPOS, "every repo gets exactly one fetch");
    let most = seen.iter().copied().max().unwrap_or(0);
    assert!(
        most <= 8,
        "{most} fetches ran at once, which is how a server's MaxStartups gets tripped"
    );
    assert!(most > 1, "the fetches ran one at a time, so a tree is slow");
}