class/class_backend/node_modules/execa/lib/error.js

'use strict';
const {signalsByName} = require('human-signals');

const getErrorPrefix = ({timedOut, timeout, errorCode, signal, signalDescription, exitCode, isCanceled}) => {
	if (timedOut) {
		return `timed out after ${timeout} milliseconds`;
	}

	if (isCanceled) {
		return 'was canceled';
	}

	if (errorCode !== undefined) {
		return `failed with ${errorCode}`;
	}

	if (signal !== undefined) {
		return `was killed with ${signal} (${signalDescription})`;
	}

	if (exitCode !== undefined) {
		return `failed with exit code ${exitCode}`;
	}

	return 'failed';
};

const makeError = ({
	stdout,
	stderr,
	all,
	error,
	signal,
	exitCode,
	command,
	timedOut,
	isCanceled,
	killed,
	parsed: {options: {timeout}}
}) => {
	// `signal` and `exitCode` emitted on `spawned.on('exit')` event can be `null`.
	// We normalize them to `undefined`
	exitCode = exitCode === null ? undefined : exitCode;
	signal = signal === null ? undefined : signal;
	const signalDescription = signal === undefined ? undefined : signalsByName[signal].description;

	const errorCode = error && error.code;

	const prefix = getErrorPrefix({timedOut, timeout, errorCode, signal, signalDescription, exitCode, isCanceled});
	const execaMessage = `Command ${prefix}: ${command}`;
	const isError = Object.prototype.toString.call(error) === '[object Error]';
	const shortMessage = isError ? `${execaMessage}\n${error.message}` : execaMessage;
	const message = [shortMessage, stderr, stdout].filter(Boolean).join('\n');

	if (isError) {
		error.originalMessage = error.message;
		error.message = message;
	} else {
		error = new Error(message);
	}

	error.shortMessage = shortMessage;
	error.command = command;
	error.exitCode = exitCode;
	error.signal = signal;
	error.signalDescription = signalDescription;
	error.stdout = stdout;
	error.stderr = stderr;

	if (all !== undefined) {
		error.all = all;
	}

	if ('bufferedData' in error) {
		delete error.bufferedData;
	}

	error.failed = true;
	error.timedOut = Boolean(timedOut);
	error.isCanceled = isCanceled;
	error.killed = killed && !timedOut;

	return error;
};

module.exports = makeError;