webpack/lib/serialization/SerializerMiddleware.js

Packs CommonJs/AMD modules for the browser. Allows to split your codebase into multiple bundles, which can be loaded on demand. Support 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
*/

"use strict";

const memorize = require("../util/memorize");

const LAZY_TARGET = Symbol("lazy serialization target");
const LAZY_SERIALIZED_VALUE = Symbol("lazy serialization data");

/**
 * @template DeserializedType
 * @template SerializedType
 */
class SerializerMiddleware {
	/* istanbul ignore next */
	/**
	 * @abstract
	 * @param {DeserializedType} data data
	 * @param {Object} context context object
	 * @returns {SerializedType|Promise<SerializedType>} serialized data
	 */
	serialize(data, context) {
		const AbstractMethodError = require("../AbstractMethodError");
		throw new AbstractMethodError();
	}

	/* istanbul ignore next */
	/**
	 * @abstract
	 * @param {SerializedType} data data
	 * @param {Object} context context object
	 * @returns {DeserializedType|Promise<DeserializedType>} deserialized data
	 */
	deserialize(data, context) {
		const AbstractMethodError = require("../AbstractMethodError");
		throw new AbstractMethodError();
	}

	/**
	 * @param {any | function(): Promise<any> | any} value contained value or function to value
	 * @param {SerializerMiddleware<any, any>} target target middleware
	 * @param {object=} options lazy options
	 * @param {any=} serializedValue serialized value
	 * @returns {function(): Promise<any> | any} lazy function
	 */
	static createLazy(value, target, options = {}, serializedValue) {
		if (SerializerMiddleware.isLazy(value, target)) return value;
		const fn = typeof value === "function" ? value : () => value;
		fn[LAZY_TARGET] = target;
		/** @type {any} */ (fn).options = options;
		fn[LAZY_SERIALIZED_VALUE] = serializedValue;
		return fn;
	}

	/**
	 * @param {function(): Promise<any> | any} fn lazy function
	 * @param {SerializerMiddleware<any, any>=} target target middleware
	 * @returns {boolean} true, when fn is a lazy function (optionally of that target)
	 */
	static isLazy(fn, target) {
		if (typeof fn !== "function") return false;
		const t = fn[LAZY_TARGET];
		return target ? t === target : !!t;
	}

	/**
	 * @param {function(): Promise<any> | any} fn lazy function
	 * @returns {object} options
	 */
	static getLazyOptions(fn) {
		if (typeof fn !== "function") return undefined;
		return /** @type {any} */ (fn).options;
	}

	/**
	 * @param {function(): Promise<any> | any} fn lazy function
	 * @returns {any} serialized value
	 */
	static getLazySerializedValue(fn) {
		if (typeof fn !== "function") return undefined;
		return fn[LAZY_SERIALIZED_VALUE];
	}

	/**
	 * @param {function(): Promise<any> | any} fn lazy function
	 * @param {any} value serialized value
	 * @returns {void}
	 */
	static setLazySerializedValue(fn, value) {
		fn[LAZY_SERIALIZED_VALUE] = value;
	}

	/**
	 * @param {function(): Promise<any> | any} lazy lazy function
	 * @param {function(any): Promise<any> | any} serialize serialize function
	 * @returns {function(): Promise<any> | any} new lazy
	 */
	static serializeLazy(lazy, serialize) {
		const fn = memorize(() => {
			const r = lazy();
			if (r instanceof Promise) return r.then(data => data && serialize(data));
			if (r) return serialize(r);
			return null;
		});
		fn[LAZY_TARGET] = lazy[LAZY_TARGET];
		/** @type {any} */ (fn).options = /** @type {any} */ (lazy).options;
		lazy[LAZY_SERIALIZED_VALUE] = fn;
		return fn;
	}

	/**
	 * @param {function(): Promise<any> | any} lazy lazy function
	 * @param {function(any): Promise<any> | any} deserialize deserialize function
	 * @returns {function(): Promise<any> | any} new lazy
	 */
	static deserializeLazy(lazy, deserialize) {
		const fn = memorize(() => {
			const r = lazy();
			if (r instanceof Promise) return r.then(data => deserialize(data));
			return deserialize(r);
		});
		fn[LAZY_TARGET] = lazy[LAZY_TARGET];
		/** @type {any} */ (fn).options = /** @type {any} */ (lazy).options;
		fn[LAZY_SERIALIZED_VALUE] = lazy;
		return fn;
	}
}

module.exports = SerializerMiddleware;