webpack/lib/dependencies/ContextDependency.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
	Author Tobias Koppers @sokra
*/

"use strict";

const Dependency = require("../Dependency");
const DependencyTemplate = require("../DependencyTemplate");
const makeSerializable = require("../util/makeSerializable");
const memoize = require("../util/memoize");

/** @typedef {import("../ContextModule").ContextOptions} ContextOptions */
/** @typedef {import("../Dependency").TRANSITIVE} TRANSITIVE */
/** @typedef {import("../ModuleGraph")} ModuleGraph */
/** @typedef {import("../WebpackError")} WebpackError */

const getCriticalDependencyWarning = memoize(() =>
	require("./CriticalDependencyWarning")
);

/** @typedef {ContextOptions & { request: string }} ContextDependencyOptions */

const regExpToString = r => (r ? r + "" : "");

class ContextDependency extends Dependency {
	/**
	 * @param {ContextDependencyOptions} options options for the context module
	 * @param {string=} context request context
	 */
	constructor(options, context) {
		super();

		this.options = options;
		this.userRequest = this.options && this.options.request;
		/** @type {false | string} */
		this.critical = false;
		this.hadGlobalOrStickyRegExp = false;

		if (
			this.options &&
			(this.options.regExp.global || this.options.regExp.sticky)
		) {
			this.options = { ...this.options, regExp: null };
			this.hadGlobalOrStickyRegExp = true;
		}

		this.request = undefined;
		this.range = undefined;
		this.valueRange = undefined;
		this.inShorthand = undefined;
		// TODO refactor this
		this.replaces = undefined;
		this._requestContext = context;
	}

	/**
	 * @returns {string | undefined} a request context
	 */
	getContext() {
		return this._requestContext;
	}

	get category() {
		return "commonjs";
	}

	/**
	 * @returns {boolean | TRANSITIVE} true, when changes to the referenced module could affect the referencing module; TRANSITIVE, when changes to the referenced module could affect referencing modules of the referencing module
	 */
	couldAffectReferencingModule() {
		return true;
	}

	/**
	 * @returns {string | null} an identifier to merge equal requests
	 */
	getResourceIdentifier() {
		return (
			`context${this._requestContext || ""}|ctx request${
				this.options.request
			} ${this.options.recursive} ` +
			`${regExpToString(this.options.regExp)} ${regExpToString(
				this.options.include
			)} ${regExpToString(this.options.exclude)} ` +
			`${this.options.mode} ${this.options.chunkName} ` +
			`${JSON.stringify(this.options.groupOptions)}`
		);
	}

	/**
	 * Returns warnings
	 * @param {ModuleGraph} moduleGraph module graph
	 * @returns {WebpackError[]} warnings
	 */
	getWarnings(moduleGraph) {
		let warnings = super.getWarnings(moduleGraph);

		if (this.critical) {
			if (!warnings) warnings = [];
			const CriticalDependencyWarning = getCriticalDependencyWarning();
			warnings.push(new CriticalDependencyWarning(this.critical));
		}

		if (this.hadGlobalOrStickyRegExp) {
			if (!warnings) warnings = [];
			const CriticalDependencyWarning = getCriticalDependencyWarning();
			warnings.push(
				new CriticalDependencyWarning(
					"Contexts can't use RegExps with the 'g' or 'y' flags."
				)
			);
		}

		return warnings;
	}

	serialize(context) {
		const { write } = context;

		write(this.options);
		write(this.userRequest);
		write(this.critical);
		write(this.hadGlobalOrStickyRegExp);
		write(this.request);
		write(this._requestContext);
		write(this.range);
		write(this.valueRange);
		write(this.prepend);
		write(this.replaces);

		super.serialize(context);
	}

	deserialize(context) {
		const { read } = context;

		this.options = read();
		this.userRequest = read();
		this.critical = read();
		this.hadGlobalOrStickyRegExp = read();
		this.request = read();
		this._requestContext = read();
		this.range = read();
		this.valueRange = read();
		this.prepend = read();
		this.replaces = read();

		super.deserialize(context);
	}
}

makeSerializable(
	ContextDependency,
	"webpack/lib/dependencies/ContextDependency"
);

ContextDependency.Template = DependencyTemplate;

module.exports = ContextDependency;