codex-wrapper 0.3.0

//! Helpers for the unix-only process-lifetime tests in [`crate::exec`] and
//! [`crate::streaming`].
//!
//! Those tests assert that a spawned `codex` dies when the future driving it
//! is dropped, which means observing the process from outside the wrapper: the
//! fake codex records its PID to a file, and the test reads that PID back and
//! watches it disappear.

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

use crate::{Codex, CodexBuilder};

/// A file that the fake codex writes its PID to, cleaned up on drop.
pub(crate) struct PidFile {
    path: PathBuf,
}

impl PidFile {
    /// Reserve a PID file path. `label` distinguishes concurrent tests, which
    /// share a process ID because cargo runs them as threads.
    pub(crate) fn new(label: &str) -> Self {
        let path =
            std::env::temp_dir().join(format!("codex-wrapper-{}-{label}.pid", std::process::id()));
        let _ = std::fs::remove_file(&path);
        Self { path }
    }

    pub(crate) fn path(&self) -> &Path {
        &self.path
    }

    /// Read back the PID the fake codex recorded, waiting up to a second for
    /// it to appear. Panics rather than returning an error: no PID means the
    /// fake never ran, which makes the calling test meaningless.
    pub(crate) async fn read_pid(&self) -> u32 {
        for _ in 0..100 {
            if let Ok(contents) = std::fs::read_to_string(&self.path)
                && let Ok(pid) = contents.trim().parse()
            {
                return pid;
            }
            tokio::time::sleep(Duration::from_millis(10)).await;
        }
        panic!("fake codex never recorded a pid at {}", self.path.display());
    }
}

impl Drop for PidFile {
    fn drop(&mut self) {
        let _ = std::fs::remove_file(&self.path);
    }
}

/// A [`Codex`] client whose binary is a fake codex that blocks until killed,
/// recording its PID to `pid_file` first.
///
/// Returned as a builder so callers can decide whether the run carries a
/// wrapper timeout or is cancelled from outside.
pub(crate) fn blocking_codex(pid_file: &PidFile) -> CodexBuilder {
    let script = Path::new(env!("CARGO_MANIFEST_DIR"))
        .join("tests")
        .join("fake-codex-blocks.sh");
    Codex::builder()
        .binary("/bin/bash")
        .arg(script.to_str().expect("fixture path is utf-8"))
        .env(
            "CODEX_WRAPPER_TEST_PIDFILE",
            pid_file.path().to_str().expect("pid file path is utf-8"),
        )
}

/// Wait for `pid` to stop running, up to five seconds.
///
/// Checks the process state rather than `kill -0`: a killed child lingers as a
/// zombie until tokio's orphan reaper collects it, and a zombie still answers
/// `kill -0`, which would read as "still running".
pub(crate) async fn wait_until_gone(pid: u32) -> bool {
    for _ in 0..250 {
        if !is_running(pid) {
            return true;
        }
        tokio::time::sleep(Duration::from_millis(20)).await;
    }
    false
}

/// Public-in-crate view of [`is_running`], for a test that asserts a process
/// is still alive rather than waiting for it to go.
pub(crate) fn is_running_for_test(pid: u32) -> bool {
    is_running(pid)
}

/// `true` while `pid` is a live process. Empty `ps` output means the PID is
/// gone; a leading `Z` means it exited and is awaiting reaping.
fn is_running(pid: u32) -> bool {
    let output = std::process::Command::new("ps")
        .args(["-o", "state=", "-p", &pid.to_string()])
        .output()
        .expect("ps must be available");
    let state = String::from_utf8_lossy(&output.stdout);
    let state = state.trim();
    !state.is_empty() && !state.starts_with('Z')
}