webpack/lib/json/JsonParser.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 Tobias Koppers @sokra
*/

"use strict";

const Parser = require("../Parser");
const JsonExportsDependency = require("../dependencies/JsonExportsDependency");
const memoize = require("../util/memoize");
const JsonData = require("./JsonData");

/** @typedef {import("../../declarations/plugins/JsonModulesPluginParser").JsonModulesPluginParserOptions} JsonModulesPluginParserOptions */
/** @typedef {import("../Module").BuildInfo} BuildInfo */
/** @typedef {import("../Module").BuildMeta} BuildMeta */
/** @typedef {import("../Parser").ParserState} ParserState */
/** @typedef {import("../Parser").PreparsedAst} PreparsedAst */
/** @typedef {import("./JsonModulesPlugin").RawJsonData} RawJsonData */

const getParseJson = memoize(() => require("json-parse-even-better-errors"));

class JsonParser extends Parser {
	/**
	 * @param {JsonModulesPluginParserOptions} options parser options
	 */
	constructor(options) {
		super();
		this.options = options || {};
	}

	/**
	 * @param {string | Buffer | PreparsedAst} source the source to parse
	 * @param {ParserState} state the parser state
	 * @returns {ParserState} the parser state
	 */
	parse(source, state) {
		if (Buffer.isBuffer(source)) {
			source = source.toString("utf-8");
		}

		/** @type {NonNullable<JsonModulesPluginParserOptions["parse"]>} */
		const parseFn =
			typeof this.options.parse === "function"
				? this.options.parse
				: getParseJson();
		/** @type {Buffer | RawJsonData | undefined} */
		let data;
		try {
			data =
				typeof source === "object"
					? source
					: parseFn(source[0] === "\ufeff" ? source.slice(1) : source);
		} catch (e) {
			throw new Error(`Cannot parse JSON: ${/** @type {Error} */ (e).message}`);
		}
		const jsonData = new JsonData(/** @type {Buffer | RawJsonData} */ (data));
		const buildInfo = /** @type {BuildInfo} */ (state.module.buildInfo);
		buildInfo.jsonData = jsonData;
		buildInfo.strict = true;
		const buildMeta = /** @type {BuildMeta} */ (state.module.buildMeta);
		buildMeta.exportsType = "default";
		buildMeta.defaultObject =
			typeof data === "object" ? "redirect-warn" : false;
		state.module.addDependency(new JsonExportsDependency(jsonData));
		return state;
	}
}

module.exports = JsonParser;