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

"use strict";

/** @typedef {import("webpack-sources").Source} Source */
/** @typedef {import("./ChunkGraph")} ChunkGraph */
/** @typedef {import("./CodeGenerationResults")} CodeGenerationResults */
/** @typedef {import("./Compilation")} Compilation */
/** @typedef {import("./ConcatenationScope")} ConcatenationScope */
/** @typedef {import("./DependencyTemplate")} DependencyTemplate */
/** @typedef {import("./DependencyTemplates")} DependencyTemplates */
/** @typedef {import("./Module").ConcatenationBailoutReasonContext} ConcatenationBailoutReasonContext */
/** @typedef {import("./Module").RuntimeRequirements} RuntimeRequirements */
/** @typedef {import("./ModuleGraph")} ModuleGraph */
/** @typedef {import("./NormalModule")} NormalModule */
/** @typedef {import("./RuntimeTemplate")} RuntimeTemplate */
/** @typedef {import("./util/Hash")} Hash */
/** @typedef {import("./util/runtime").RuntimeSpec} RuntimeSpec */

/**
 * @typedef {object} GenerateContext
 * @property {DependencyTemplates} dependencyTemplates mapping from dependencies to templates
 * @property {RuntimeTemplate} runtimeTemplate the runtime template
 * @property {ModuleGraph} moduleGraph the module graph
 * @property {ChunkGraph} chunkGraph the chunk graph
 * @property {RuntimeRequirements} runtimeRequirements the requirements for runtime
 * @property {RuntimeSpec} runtime the runtime
 * @property {ConcatenationScope=} concatenationScope when in concatenated module, information about other concatenated modules
 * @property {CodeGenerationResults=} codeGenerationResults code generation results of other modules (need to have a codeGenerationDependency to use that)
 * @property {string} type which kind of code should be generated
 * @property {function(): Map=} getData get access to the code generation data
 */

/**
 * @typedef {object} UpdateHashContext
 * @property {NormalModule} module the module
 * @property {ChunkGraph} chunkGraph
 * @property {RuntimeSpec} runtime
 * @property {RuntimeTemplate=} runtimeTemplate
 */

/**
 *
 */
class Generator {
	/**
	 * @param {Record} map map of types
	 * @returns {ByTypeGenerator} generator by type
	 */
	static byType(map) {
		return new ByTypeGenerator(map);
	}

	/* istanbul ignore next */
	/**
	 * @abstract
	 * @param {NormalModule} module fresh module
	 * @returns {Set} available types (do not mutate)
	 */
	getTypes(module) {
		const AbstractMethodError = require("./AbstractMethodError");
		throw new AbstractMethodError();
	}

	/* istanbul ignore next */
	/**
	 * @abstract
	 * @param {NormalModule} module the module
	 * @param {string=} type source type
	 * @returns {number} estimate size of the module
	 */
	getSize(module, type) {
		const AbstractMethodError = require("./AbstractMethodError");
		throw new AbstractMethodError();
	}

	/* istanbul ignore next */
	/**
	 * @abstract
	 * @param {NormalModule} module module for which the code should be generated
	 * @param {GenerateContext} generateContext context for generate
	 * @returns {Source} generated code
	 */
	generate(
		module,
		{ dependencyTemplates, runtimeTemplate, moduleGraph, type }
	) {
		const AbstractMethodError = require("./AbstractMethodError");
		throw new AbstractMethodError();
	}

	/**
	 * @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 `Module Concatenation is not implemented for ${this.constructor.name}`;
	}

	/**
	 * @param {Hash} hash hash that will be modified
	 * @param {UpdateHashContext} updateHashContext context for updating hash
	 */
	updateHash(hash, { module, runtime }) {
		// no nothing
	}
}

class ByTypeGenerator extends Generator {
	/**
	 * @param {Record} map map of types
	 */
	constructor(map) {
		super();
		this.map = map;
		this._types = new Set(Object.keys(map));
	}

	/**
	 * @param {NormalModule} module fresh module
	 * @returns {Set} available types (do not mutate)
	 */
	getTypes(module) {
		return this._types;
	}

	/**
	 * @param {NormalModule} module the module
	 * @param {string=} type source type
	 * @returns {number} estimate size of the module
	 */
	getSize(module, type) {
		const t = type || "javascript";
		const generator = this.map[t];
		return generator ? generator.getSize(module, t) : 0;
	}

	/**
	 * @param {NormalModule} module module for which the code should be generated
	 * @param {GenerateContext} generateContext context for generate
	 * @returns {Source} generated code
	 */
	generate(module, generateContext) {
		const type = generateContext.type;
		const generator = this.map[type];
		if (!generator) {
			throw new Error(`Generator.byType: no generator specified for ${type}`);
		}
		return generator.generate(module, generateContext);
	}
}

module.exports = Generator;