webpack/lib/runtime/BaseUriRuntimeModule.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 Ivan Kopeykin @vankop
*/

"use strict";

const RuntimeGlobals = require("../RuntimeGlobals");
const RuntimeModule = require("../RuntimeModule");
const { renderBaseUri } = require("./baseUri");

/**
 * @import {
 * 	EntryDescriptionNormalized as EntryDescription
 * } from "../../declarations/WebpackOptions"
 */
/** @import Chunk from "../Chunk" */
/** @import Compilation from "../Compilation" */

class BaseUriRuntimeModule extends RuntimeModule {
	constructor() {
		super("base uri", RuntimeModule.STAGE_ATTACH);
	}

	/**
	 * Returns true, if the runtime module should get it's own scope.
	 * When false, `generate()` must emit complete statements ending with `;`
	 * so a following runtime IIFE is not parsed as a call (ASI).
	 * @returns {boolean} true, if the runtime module should get it's own scope
	 */
	shouldIsolate() {
		return false;
	}

	/**
	 * Generates runtime code for this runtime module.
	 * @returns {string | null} runtime code
	 */
	generate() {
		const chunk = /** @type {Chunk} */ (this.chunk);
		const options =
			/** @type {EntryDescription} */
			(chunk.getEntryOptions());
		if (options.baseUri === undefined) {
			return `${RuntimeGlobals.baseURI} = undefined;`;
		}
		const { runtimeTemplate, outputOptions } =
			/** @type {Compilation} */
			(this.compilation);
		// Chunk loading is off here, so no loader has named a base for a relative one to be
		// read against. Module output carries its own url; anything else has none to offer.
		if (!runtimeTemplate.isModule()) {
			return `${RuntimeGlobals.baseURI} = ${JSON.stringify(options.baseUri)};`;
		}
		return renderBaseUri(
			options.baseUri,
			`${outputOptions.importMetaName}.url`
		);
	}
}

module.exports = BaseUriRuntimeModule;