google-closure-library/closure/goog/dom/textassert.js

Google's common JavaScript library

/**
 * @license
 * Copyright The Closure Library Authors.
 * SPDX-License-Identifier: Apache-2.0
 */

/**
 * Utilities intended for refactoring legacy code; allows classifying strings
 * into plain text that does not contain HTML and HTML. Please do NOT use in new
 * code.
 */

goog.provide('goog.dom.textAssert');

goog.require('goog.asserts');
goog.require('goog.dom');
goog.require('goog.dom.TagName');

/**
 * Assert that the string is plain text that does not have HTML, i.e. not
 * affected by HTML escaping. Otherwise, this raises an error if assertions are
 * enabled. It does NOT sanitize nor make any change to the input string. It
 * should only be used when the assertion failure is benign, such as printing
 * spurious tags. DO NOT count on this to remove unsafe HTML. It is only meant
 * for legacy refactoring. Please do NOT use in new code.
 * @param {string} text
 * @return {string}
 */
goog.dom.textAssert.assertHtmlFree = function(text) {
  'use strict';
  if (goog.asserts.ENABLE_ASSERTS) {
    var elmt = goog.dom.createElement(goog.dom.TagName.BODY);
    elmt.textContent = text;
    goog.asserts.assert(
        elmt.innerHTML == elmt.textContent,
        'String has HTML original: %s, escaped: %s', text, elmt.innerHTML);
  }
  return text;
};