import { spawn, spawnSync } from "node:child_process";

import { once } from "node:events";

import { watch } from "node:fs";

import fs from "node:fs/promises";

import path from "node:path";

import { afterEach, describe, expect, it } from "vitest";

);

}

async function waitForFile(filePath: string, timeoutMs: number): Promise<string> {

try {

return await fs.readFile(filePath, "utf8");

} catch {

// Wait below.

async function waitForJsonFile<T>(filePath: string, timeoutMs: number): Promise<T> {

const deadline = Date.now() + timeoutMs;

let lastError: unknown;

while (Date.now() <= deadline) {

try {

return JSON.parse(await fs.readFile(filePath, "utf8")) as T;

} catch (error) {

lastError = error;

await new Promise((resolve) => setTimeout(resolve, 25));

}

}

const signal = AbortSignal.timeout(timeoutMs);

return await new Promise<string>((resolve, reject) => {

let settled = false;

let watcher: ReturnType<typeof watch> | undefined;

const fileName = path.basename(filePath);

const cleanup = () => {

if (settled) {

return;

}

settled = true;

watcher?.close();

};

const tryRead = async () => {

try {

const content = await fs.readFile(filePath, "utf8");

cleanup();

resolve(content);

} catch {

// Keep watching until the deadline aborts.

}

};

signal.addEventListener(

"abort",

() => {

cleanup();

reject(new Error(`timed out waiting for ${filePath}`));

},

{ once: true },

);

watcher = watch(path.dirname(filePath), { signal }, (_event, changedFileName) => {

if (!changedFileName || changedFileName.toString() === fileName) {

void tryRead();

}

});

void tryRead();

});

throw new Error(`timed out waiting for parseable JSON in ${filePath}`, { cause: lastError });

}

async function waitForProcessExit(

let respawnChildPid: number | undefined;

try {

const childInfo = JSON.parse(await waitForFile(childInfoPath, 5000)) as { pid: number };

const childInfo = await waitForJsonFile<{ pid: number }>(childInfoPath, 5000);

respawnChildPid = childInfo.pid;

launcher.kill("SIGTERM");

let respawnChildPid: number | undefined;

try {

const childInfo = JSON.parse(await waitForFile(childInfoPath, 5000)) as { pid: number };

const childInfo = await waitForJsonFile<{ pid: number }>(childInfoPath, 5000);

respawnChildPid = childInfo.pid;

launcher.kill("SIGTERM");