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 parseJson = require("../util/parseJson");
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("../util/fs").JsonValue} JsonValue */

/** @typedef {(input: string) => Buffer | JsonValue} ParseFn */

/**
 * Defines the function returning type used by this module.
 * @template T
 * @typedef {import("../util/memoize").FunctionReturning<T>} FunctionReturning
 */

class JsonParser extends Parser {
	/**
	 * Creates an instance of JsonParser.
	 * @param {JsonModulesPluginParserOptions} options parser options
	 */
	constructor(options = {}) {
		super();
		/** @type {JsonModulesPluginParserOptions} */
		this.options = options;
	}

	/**
	 * Parses the provided source and updates the parser state.
	 * @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("utf8");
		}

		/** @type {typeof parseJson} */
		const parseFn =
			typeof this.options.parse === "function" ? this.options.parse : parseJson;
		/** @type {Buffer | JsonValue | undefined} */
		let data;
		try {
			data =
				typeof source === "object"
					? source
					: parseFn(source[0] === "\uFEFF" ? source.slice(1) : source);
		} catch (err) {
			throw new Error(
				`Cannot parse JSON: ${/** @type {Error} */ (err).message}`,
				{ cause: err }
			);
		}
		const jsonData = new JsonData(/** @type {Buffer | JsonValue} */ (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"
				? this.options.namedExports === false
					? false
					: this.options.namedExports === true
						? "redirect"
						: "redirect-warn"
				: false;
		state.module.addDependency(
			new JsonExportsDependency(
				jsonData,
				/** @type {number} */
				(this.options.exportsDepth)
			)
		);
		return state;
	}
}

module.exports = JsonParser;