webpack/lib/container/options.js

Packs ECMAScript/CommonJs/AMD modules for the browser. Allows you to split your codebase into multiple bundles, which can be loaded on demand. Supports loaders to preprocess files, i.e. json, jsx, es7, css, less, ... and your custom stuff.

/*
	MIT License http://www.opensource.org/licenses/mit-license.php
	Author Tobias Koppers @sokra
*/

"use strict";

/**
 * @template T
 * @typedef {Record<string, string | string[] | T>} Item
 */

/**
 * @template T
 * @typedef {(string | Item<T>)[] | Item<T>} ContainerOptionsFormat
 */

/**
 * @template T
 * @template N
 * @param {ContainerOptionsFormat<T>} options options passed by the user
 * @param {(item: string | string[], itemOrKey: string) => N} normalizeSimple normalize a simple item
 * @param {(value: T, key: string) => N} normalizeOptions normalize a complex item
 * @param {(item: string, normalized: N) => void} fn processing function
 * @returns {void}
 */
const process = (options, normalizeSimple, normalizeOptions, fn) => {
	/**
	 * @param {(string | Item<T>)[]} items items
	 */
	const array = items => {
		for (const item of items) {
			if (typeof item === "string") {
				fn(item, normalizeSimple(item, item));
			} else if (item && typeof item === "object") {
				object(item);
			} else {
				throw new Error("Unexpected options format");
			}
		}
	};
	/**
	 * @param {Item<T>} obj an object
	 */
	const object = obj => {
		for (const [key, value] of Object.entries(obj)) {
			if (typeof value === "string" || Array.isArray(value)) {
				fn(key, normalizeSimple(value, key));
			} else {
				fn(key, normalizeOptions(value, key));
			}
		}
	};
	if (!options) {
		// Do nothing
	} else if (Array.isArray(options)) {
		array(options);
	} else if (typeof options === "object") {
		object(options);
	} else {
		throw new Error("Unexpected options format");
	}
};

/**
 * @template T
 * @template R
 * @param {ContainerOptionsFormat<T>} options options passed by the user
 * @param {(item: string | string[], itemOrKey: string) => R} normalizeSimple normalize a simple item
 * @param {(value: T, key: string) => R} normalizeOptions normalize a complex item
 * @returns {[string, R][]} parsed options
 */
const parseOptions = (options, normalizeSimple, normalizeOptions) => {
	/** @type {[string, R][]} */
	const items = [];
	process(options, normalizeSimple, normalizeOptions, (key, value) => {
		items.push([key, value]);
	});
	return items;
};

/**
 * @template T
 * @param {string} scope scope name
 * @param {ContainerOptionsFormat<T>} options options passed by the user
 * @returns {Record<string, string | string[] | T>} options to spread or pass
 */
const scope = (scope, options) => {
	/** @type {Record<string, string | string[] | T>} */
	const obj = {};
	process(
		options,
		item => /** @type {string | string[] | T} */ (item),
		item => /** @type {string | string[] | T} */ (item),
		(key, value) => {
			obj[
				key.startsWith("./") ? `${scope}${key.slice(1)}` : `${scope}/${key}`
			] = value;
		}
	);
	return obj;
};

module.exports.parseOptions = parseOptions;
module.exports.scope = scope;