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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";

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

/** @typedef {import("webpack-sources").Source} Source */
/** @typedef {import("../ExportsInfo")} ExportsInfo */
/** @typedef {import("../Generator").GenerateContext} GenerateContext */
/** @typedef {import("../Module").ConcatenationBailoutReasonContext} ConcatenationBailoutReasonContext */
/** @typedef {import("../NormalModule")} NormalModule */
/** @typedef {import("../util/runtime").RuntimeSpec} RuntimeSpec */
/** @typedef {import("./JsonData")} JsonData */
/** @typedef {import("./JsonModulesPlugin").RawJsonData} RawJsonData */

/**
 * @param {RawJsonData} data Raw JSON data
 * @returns {undefined|string} stringified data
 */
const stringifySafe = data => {
	const stringified = JSON.stringify(data);
	if (!stringified) {
		return undefined; // Invalid JSON
	}

	return stringified.replace(/\u2028|\u2029/g, str =>
		str === "\u2029" ? "\\u2029" : "\\u2028"
	); // invalid in JavaScript but valid JSON
};

/**
 * @param {RawJsonData} data Raw JSON data (always an object or array)
 * @param {ExportsInfo} exportsInfo exports info
 * @param {RuntimeSpec} runtime the runtime
 * @returns {RawJsonData} reduced data
 */
const createObjectForExportsInfo = (data, exportsInfo, runtime) => {
	if (exportsInfo.otherExportsInfo.getUsed(runtime) !== UsageState.Unused)
		return data;
	const isArray = Array.isArray(data);
	/** @type {RawJsonData} */
	const reducedData = isArray ? [] : {};
	for (const key of Object.keys(data)) {
		const exportInfo = exportsInfo.getReadOnlyExportInfo(key);
		const used = exportInfo.getUsed(runtime);
		if (used === UsageState.Unused) continue;

		/** @type {RawJsonData} */
		let value;
		if (used === UsageState.OnlyPropertiesUsed && exportInfo.exportsInfo) {
			value = createObjectForExportsInfo(
				data[key],
				exportInfo.exportsInfo,
				runtime
			);
		} else {
			value = data[key];
		}

		const name = /** @type {string} */ (exportInfo.getUsedName(key, runtime));
		/** @type {Record} */ (reducedData)[name] = value;
	}
	if (isArray) {
		let arrayLengthWhenUsed =
			exportsInfo.getReadOnlyExportInfo("length").getUsed(runtime) !==
			UsageState.Unused
				? data.length
				: undefined;

		let sizeObjectMinusArray = 0;
		for (let i = 0; i < reducedData.length; i++) {
			if (reducedData[i] === undefined) {
				sizeObjectMinusArray -= 2;
			} else {
				sizeObjectMinusArray += `${i}`.length + 3;
			}
		}
		if (arrayLengthWhenUsed !== undefined) {
			sizeObjectMinusArray +=
				`${arrayLengthWhenUsed}`.length +
				8 -
				(arrayLengthWhenUsed - reducedData.length) * 2;
		}
		if (sizeObjectMinusArray < 0)
			return Object.assign(
				arrayLengthWhenUsed === undefined
					? {}
					: { length: arrayLengthWhenUsed },
				reducedData
			);
		/** @type {number} */
		const generatedLength =
			arrayLengthWhenUsed !== undefined
				? Math.max(arrayLengthWhenUsed, reducedData.length)
				: reducedData.length;
		for (let i = 0; i < generatedLength; i++) {
			if (reducedData[i] === undefined) {
				reducedData[i] = 0;
			}
		}
	}
	return reducedData;
};

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

class JsonGenerator extends Generator {
	/**
	 * @param {NormalModule} module fresh module
	 * @returns {Set} 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) {
		/** @type {RawJsonData | undefined} */
		const data =
			module.buildInfo &&
			module.buildInfo.jsonData &&
			module.buildInfo.jsonData.get();
		if (!data) return 0;
		return /** @type {string} */ (stringifySafe(data)).length + 10;
	}

	/**
	 * @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 module for which the code should be generated
	 * @param {GenerateContext} generateContext context for generate
	 * @returns {Source} generated code
	 */
	generate(
		module,
		{
			moduleGraph,
			runtimeTemplate,
			runtimeRequirements,
			runtime,
			concatenationScope
		}
	) {
		/** @type {RawJsonData | undefined} */
		const data =
			module.buildInfo &&
			module.buildInfo.jsonData &&
			module.buildInfo.jsonData.get();
		if (data === undefined) {
			return new RawSource(
				runtimeTemplate.missingModuleStatement({
					request: module.rawRequest
				})
			);
		}
		const exportsInfo = moduleGraph.getExportsInfo(module);
		/** @type {RawJsonData} */
		let finalJson =
			typeof data === "object" &&
			data &&
			exportsInfo.otherExportsInfo.getUsed(runtime) === UsageState.Unused
				? createObjectForExportsInfo(data, exportsInfo, runtime)
				: data;
		// Use JSON because JSON.parse() is much faster than JavaScript evaluation
		const jsonStr = /** @type {string} */ (stringifySafe(finalJson));
		const jsonExpr =
			jsonStr.length > 20 && typeof finalJson === "object"
				? `/*#__PURE__*/JSON.parse('${jsonStr.replace(/[\\']/g, "\\$&")}')`
				: jsonStr;
		/** @type {string} */
		let content;
		if (concatenationScope) {
			content = `${runtimeTemplate.supportsConst() ? "const" : "var"} ${
				ConcatenationScope.NAMESPACE_OBJECT_EXPORT
			} = ${jsonExpr};`;
			concatenationScope.registerNamespaceExport(
				ConcatenationScope.NAMESPACE_OBJECT_EXPORT
			);
		} else {
			runtimeRequirements.add(RuntimeGlobals.module);
			content = `${module.moduleArgument}.exports = ${jsonExpr};`;
		}
		return new RawSource(content);
	}
}

module.exports = JsonGenerator;