jest-worker/build/threadChild.mjs

import { createRequire } from "node:module";
import { isMainThread, parentPort } from "worker_threads";
import { isPromise } from "jest-util";
import { serialize } from "@ungap/structured-clone";

//#region rolldown:runtime
var __require = /* @__PURE__ */ createRequire(import.meta.url);

//#endregion
//#region src/types.ts
const CHILD_MESSAGE_INITIALIZE = 0;
const CHILD_MESSAGE_CALL = 1;
const CHILD_MESSAGE_END = 2;
const CHILD_MESSAGE_MEM_USAGE = 3;
const CHILD_MESSAGE_CALL_SETUP = 4;
const PARENT_MESSAGE_OK = 0;
const PARENT_MESSAGE_CLIENT_ERROR = 1;
const PARENT_MESSAGE_SETUP_ERROR = 2;
const PARENT_MESSAGE_MEM_USAGE = 4;

//#endregion
//#region src/workers/isDataCloneError.ts
/**
* Copyright (c) Meta Platforms, Inc. and affiliates.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*/
const DATA_CLONE_ERROR_CODE = 25;
/**
* Unfortunately, [`util.types.isNativeError(value)`](https://nodejs.org/api/util.html#utiltypesisnativeerrorvalue)
* return `false` for `DataCloneError` error.
* For this reason, try to detect it in this way
*/
function isDataCloneError(error) {
	return error != null && typeof error === "object" && "name" in error && error.name === "DataCloneError" && "message" in error && typeof error.message === "string" && "code" in error && error.code === DATA_CLONE_ERROR_CODE;
}

//#endregion
//#region src/workers/safeMessageTransferring.ts
function packMessage(message) {
	return {
		__STRUCTURED_CLONE_SERIALIZED__: true,
		data: serialize(message, { json: true })
	};
}

//#endregion
//#region src/workers/threadChild.ts
let file = null;
let setupArgs = [];
let initialized = false;
/**
* This file is a small bootstrapper for workers. It sets up the communication
* between the worker and the parent process, interpreting parent messages and
* sending results back.
*
* The file loaded will be lazily initialized the first time any of the workers
* is called. This is done for optimal performance: if the farm is initialized,
* but no call is made to it, child Node processes will be consuming the least
* possible amount of memory.
*
* If an invalid message is detected, the child will exit (by throwing) with a
* non-zero exit code.
*/
const messageListener = (request) => {
	switch (request[0]) {
		case CHILD_MESSAGE_INITIALIZE:
			const init = request;
			file = init[2];
			setupArgs = init[3];
			process.env.JEST_WORKER_ID = init[4];
			break;
		case CHILD_MESSAGE_CALL:
			const call = request;
			execMethod(call[2], call[3]);
			break;
		case CHILD_MESSAGE_END:
			end();
			break;
		case CHILD_MESSAGE_MEM_USAGE:
			reportMemoryUsage();
			break;
		case CHILD_MESSAGE_CALL_SETUP:
			if (initialized) reportSuccess(void 0);
			else {
				const main = __require(file);
				initialized = true;
				if (main.setup) execFunction(main.setup, main, setupArgs, reportSuccess, reportInitializeError);
				else reportSuccess(void 0);
			}
			break;
		default: throw new TypeError(`Unexpected request from parent process: ${request[0]}`);
	}
};
parentPort.on("message", messageListener);
function reportMemoryUsage() {
	if (isMainThread) throw new Error("Child can only be used on a forked process");
	const msg = [PARENT_MESSAGE_MEM_USAGE, process.memoryUsage().heapUsed];
	parentPort.postMessage(msg);
}
function reportSuccess(result) {
	if (isMainThread) throw new Error("Child can only be used on a forked process");
	try {
		parentPort.postMessage([PARENT_MESSAGE_OK, result]);
	} catch (error) {
		let resolvedError = error;
		if (isDataCloneError(error)) try {
			parentPort.postMessage([PARENT_MESSAGE_OK, packMessage(result)]);
			return;
		} catch (secondTryError) {
			resolvedError = secondTryError;
		}
		reportClientError(resolvedError);
	}
}
function reportClientError(error) {
	return reportError(error, PARENT_MESSAGE_CLIENT_ERROR);
}
function reportInitializeError(error) {
	return reportError(error, PARENT_MESSAGE_SETUP_ERROR);
}
function reportError(error, type) {
	if (isMainThread) throw new Error("Child can only be used on a forked process");
	if (error == null) error = new Error("\"null\" or \"undefined\" thrown");
	parentPort.postMessage([
		type,
		error.constructor && error.constructor.name,
		error.message,
		error.stack,
		typeof error === "object" ? { ...error } : error
	]);
}
function end() {
	const main = __require(file);
	if (!main.teardown) {
		exitProcess();
		return;
	}
	execFunction(main.teardown, main, [], exitProcess, exitProcess);
}
function exitProcess() {
	parentPort.removeListener("message", messageListener);
}
function execMethod(method, args) {
	const main = __require(file);
	let fn;
	if (method === "default") fn = main.__esModule ? main.default : main;
	else fn = main[method];
	function execHelper() {
		execFunction(fn, main, args, reportSuccess, reportClientError);
	}
	if (initialized || !main.setup) {
		execHelper();
		return;
	}
	initialized = true;
	execFunction(main.setup, main, setupArgs, execHelper, reportInitializeError);
}
function execFunction(fn, ctx, args, onResult, onError) {
	let result;
	try {
		result = fn.apply(ctx, args);
	} catch (error) {
		onError(error);
		return;
	}
	if (isPromise(result)) result.then(onResult, onError);
	else onResult(result);
}

//#endregion