webpack/lib/json/jsonMinify.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 sheo13666q @sheo13666q
*/

"use strict";

/**
 * A `minify` function for `minimizer-webpack-plugin` that drops the whitespace
 * between a JSON asset's tokens and keeps every token as written. Source that is
 * not valid JSON is returned unchanged rather than failing the build.
 * @param {{ [file: string]: string | Buffer }} input a single `{ filename: code }` entry; a `Buffer` is read as UTF-8
 * @returns {Promise<{ code: string }>} the minified JSON
 */
const jsonMinify = async (input) => {
	// WHY: the body is self-contained because the plugin ships this function to
	// its worker pool as source. Re-serializing through `JSON.parse` would round
	// `9007199254740993` to `…992` and turn `1e400` into `null`, so only the
	// whitespace goes; `JSON.parse` is asked solely whether the source is JSON.
	const [[, source]] = Object.entries(input);
	const code = typeof source === "string" ? source : source.toString("utf8");
	try {
		JSON.parse(code);
	} catch (_err) {
		return { code };
	}
	let result = "";
	let start = 0;
	let inString = false;
	for (let i = 0; i < code.length; i++) {
		const charCode = code.charCodeAt(i);
		if (inString) {
			// A backslash always escapes the one character after it.
			if (charCode === 92) i++;
			else if (charCode === 34) inString = false;
		} else if (charCode === 34) {
			inString = true;
		} else if (
			charCode === 32 ||
			charCode === 10 ||
			charCode === 13 ||
			charCode === 9
		) {
			result += code.slice(start, i);
			start = i + 1;
		}
	}
	return { code: result + code.slice(start) };
};

// Worker-safe (the body reaches nothing outside itself), so it may run in the
// shared worker-thread pool alongside jsMinify.
jsonMinify.supportsWorkerThreads = () => true;

/**
 * The language this minifies, for a caller dispatching source that carries no
 * filename of its own.
 * @returns {string[]} the languages
 */
jsonMinify.getTypes = () => ["json"];

/**
 * @param {string} name asset filename
 * @returns {boolean} true for JSON assets, a web app manifest included
 */
jsonMinify.filter = (name) =>
	/^[^?#]*\.(?:json|webmanifest)(?:[?#].*)?$/i.test(name);

module.exports = jsonMinify;