rivy / js.os-paths

/* eslint complexity: ['error', { max: 10 }] */ // set maximum cyclomatic complexity to 10; ref: <https://eslint.org/docs/rules/complexity>

// # spell-checker:ignore AllUsersProfile HomeDrive HomePath LocalAppData UserProfile WinDir cyclomatic falsey

import * as os from 'os';

import * as path from 'path';

export type OSPaths = {

	new (): OSPaths;

	(): OSPaths;

	readonly home: () => string | undefined;

	readonly temp: () => string;

};

const { env } = process;

const isWinOS = /^win/i.test(process.platform);

function isEmpty(s: string | null | undefined): boolean {

	return !s; // reminder: JS "falsey" == [undefined, null, NaN, 0, '', false]

}

function normalizePath(path_: string | undefined): string | undefined {

	return path_ ? path.normalize(path.join(path_, '.')) : void 0;

}

const base = () => {

	const home = () =>

		normalizePath((typeof os.homedir === 'function' ? os.homedir() : void 0) || env.HOME);

	const temp = () => {

		const fallback = '/tmp';

		const priorityList = [

			typeof os.tmpdir === 'function' ? os.tmpdir() : void 0,

			env.TMPDIR,

			env.TEMP,

			env.TMP,

		];

		return normalizePath(priorityList.find((v) => !isEmpty(v))) || fallback;

	};

	return { home, temp };

};

const windows = () => {

	const home = () => {

		const priorityList = [

			typeof os.homedir === 'function' ? os.homedir() : void 0,

			env.USERPROFILE,

			env.HOME,

			env.HOMEDRIVE || env.HOMEPATH ? path.join(env.HOMEDRIVE || '', env.HOMEPATH || '') : void 0,

		];

		return normalizePath(priorityList.find((v) => !isEmpty(v)));

	};

	const temp = () => {

		const fallback = 'C:\\Temp';

		const priorityList = [

			typeof os.tmpdir === 'function' ? os.tmpdir() : void 0,

			env.TEMP,

			env.TMP,

			env.LOCALAPPDATA ? path.join(env.LOCALAPPDATA, 'Temp') : void 0,

			(function (s) {

				return s ? path.join(s, 'AppData', 'Local', 'Temp') : void 0;

			})(home()),

			env.ALLUSERSPROFILE ? path.join(env.ALLUSERSPROFILE, 'Temp') : void 0,

			env.SystemRoot ? path.join(env.SystemRoot, 'Temp') : void 0,

			env.windir ? path.join(env.windir, 'Temp') : void 0,

			env.SystemDrive ? path.join(env.SystemDrive + '\\', 'Temp') : void 0,

		];

		return normalizePath(priorityList.find((v) => !isEmpty(v))) || fallback;

	};

	return { home, temp };

};

// eslint-disable-next-line functional/no-class

class _OSPaths {

	constructor() {

		const OSPaths = function () {

			return new _OSPaths();

		};

		// Connect to platform-specific API functions by extension

		const extension = isWinOS ? windows() : base();

		OSPaths.home = extension.home;

		OSPaths.temp = extension.temp;

		return OSPaths;

	}

}

const default_ = new _OSPaths() as OSPaths;

export default default_;