AssetSourceGenerator.js 2.6 KB
/*
	MIT License http://www.opensource.org/licenses/mit-license.php
	Author Sergey Melyukov @smelukov
*/

"use strict";

const { RawSource } = require("webpack-sources");
const ConcatenationScope = require("../ConcatenationScope");
const Generator = require("../Generator");
const RuntimeGlobals = require("../RuntimeGlobals");

/** @typedef {import("webpack-sources").Source} Source */
/** @typedef {import("../Generator").GenerateContext} GenerateContext */
/** @typedef {import("../Module").ConcatenationBailoutReasonContext} ConcatenationBailoutReasonContext */
/** @typedef {import("../NormalModule")} NormalModule */

const TYPES = new Set(["javascript"]);

class AssetSourceGenerator extends Generator {
	/**
	 * @param {NormalModule} module module for which the code should be generated
	 * @param {GenerateContext} generateContext context for generate
	 * @returns {Source} generated code
	 */
	generate(
		module,
		{ concatenationScope, chunkGraph, runtimeTemplate, runtimeRequirements }
	) {
		const originalSource = module.originalSource();

		if (!originalSource) {
			return new RawSource("");
		}

		const content = originalSource.source();

		let encodedSource;
		if (typeof content === "string") {
			encodedSource = content;
		} else {
			encodedSource = content.toString("utf-8");
		}

		let sourceContent;
		if (concatenationScope) {
			concatenationScope.registerNamespaceExport(
				ConcatenationScope.NAMESPACE_OBJECT_EXPORT
			);
			sourceContent = `${runtimeTemplate.supportsConst() ? "const" : "var"} ${
				ConcatenationScope.NAMESPACE_OBJECT_EXPORT
			} = ${JSON.stringify(encodedSource)};`;
		} else {
			runtimeRequirements.add(RuntimeGlobals.module);
			sourceContent = `${RuntimeGlobals.module}.exports = ${JSON.stringify(
				encodedSource
			)};`;
		}
		return new RawSource(sourceContent);
	}

	/**
	 * @param {NormalModule} module module for which the bailout reason should be determined
	 * @param {ConcatenationBailoutReasonContext} context context
	 * @returns {string | undefined} reason why this module can't be concatenated, undefined when it can be concatenated
	 */
	getConcatenationBailoutReason(module, context) {
		return undefined;
	}

	/**
	 * @param {NormalModule} module fresh module
	 * @returns {Set<string>} available types (do not mutate)
	 */
	getTypes(module) {
		return TYPES;
	}

	/**
	 * @param {NormalModule} module the module
	 * @param {string=} type source type
	 * @returns {number} estimate size of the module
	 */
	getSize(module, type) {
		const originalSource = module.originalSource();

		if (!originalSource) {
			return 0;
		}

		// Example: m.exports="abcd"
		return originalSource.size() + 12;
	}
}

module.exports = AssetSourceGenerator;