import { type ChildProcess, spawn } from "node:child_process";
import { EventEmitter } from "node:events";
import { describe, expect, it } from "vitest";
import { isProcessAlive, isZombieProcess, waitForChildProcess } from "../src/utils/child-process.js";
describe("waitForChildProcess", () => {
it("reports signaled already-exited children as failures", async () => {
const child = Object.assign(new EventEmitter(), {
stdout: null,
stderr: null,
exitCode: null,
signalCode: "SIGTERM" as NodeJS.Signals,
});
await expect(waitForChildProcess(child as unknown as ChildProcess)).resolves.toBe(143);
});
});
describe("process liveness", () => {
it("treats the current process as alive and not a zombie", () => {
expect(isProcessAlive(process.pid)).toBe(true);
expect(isZombieProcess(process.pid)).toBe(false);
});
it("treats an exited process as dead", async () => {
const child = spawn(process.execPath, ["--eval", "process.exit(0)"], { stdio: "ignore" });
await new Promise<void>((resolveExit) => child.once("exit", () => resolveExit()));
await new Promise((resolveDelay) => setTimeout(resolveDelay, 50));
expect(isProcessAlive(child.pid!)).toBe(false);
});
it.skipIf(process.platform === "win32")("treats a zombie process as dead", async () => {
const parent = spawn(
"perl",
["-e", '$| = 1; my $pid = fork(); if ($pid) { print "$pid\\n"; sleep 30 } else { exit 0 }'],
{ stdio: ["ignore", "pipe", "ignore"] },
);
try {
const zombiePid = await new Promise<number>((resolvePid, rejectPid) => {
let output = "";
const timer = setTimeout(() => rejectPid(new Error("Timed out waiting for the zombie pid")), 5000);
parent.stdout.on("data", (chunk: Buffer) => {
output += chunk.toString();
const parsed = Number.parseInt(output.trim(), 10);
if (Number.isInteger(parsed) && parsed > 0) {
clearTimeout(timer);
resolvePid(parsed);
}
});
});
const deadline = Date.now() + 5000;
while (!isZombieProcess(zombiePid) && Date.now() < deadline) {
await new Promise((resolveDelay) => setTimeout(resolveDelay, 25));
}
expect(isZombieProcess(zombiePid)).toBe(true);
expect(isProcessAlive(zombiePid)).toBe(false);
} finally {
parent.kill("SIGKILL");
}
});
});