webpack/lib/util/propertyName.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 SAFE_IDENTIFIER = /^[_a-zA-Z$][_a-zA-Z$0-9]*$/;
const RESERVED_IDENTIFIER = new Set([
	"break",
	"case",
	"catch",
	"class",
	"const",
	"continue",
	"debugger",
	"default",
	"delete",
	"do",
	"else",
	"export",
	"extends",
	"finally",
	"for",
	"function",
	"if",
	"import",
	"in",
	"instanceof",
	"new",
	"return",
	"super",
	"switch",
	"this",
	"throw",
	"try",
	"typeof",
	"var",
	"void",
	"while",
	"with",
	"enum",
	// strict mode
	"implements",
	"interface",
	"let",
	"package",
	"private",
	"protected",
	"public",
	"static",
	"yield",
	"yield",
	// module code
	"await",
	// skip future reserved keywords defined under ES1 till ES3
	// additional
	"null",
	"true",
	"false"
]);

/**
 * @summary Returns a valid JS property name for the given property.
 * Certain strings like "default", "null", and names with whitespace are not
 * valid JS property names, so they are returned as strings.
 *
 * @param {string} prop property name to analyze
 * @returns {string} valid JS property name
 */
const propertyName = prop => {
	if (SAFE_IDENTIFIER.test(prop) && !RESERVED_IDENTIFIER.has(prop)) {
		return prop;
	} else {
		return JSON.stringify(prop);
	}
};

module.exports = { SAFE_IDENTIFIER, RESERVED_IDENTIFIER, propertyName };