yoastseo-dep/src/markers/addMarkSingleWord.js

Yoast clientside page analysis

import { stripWordBoundariesStart, stripWordBoundariesEnd } from "../languageProcessing/helpers/sanitize/stripWordBoundaries";
import { escapeRegExp } from "lodash-es";

/**
 * Marks a text with HTML tags, deals with word boundaries that were matched by regexes, but which should not be marked.
 *
 * @param {string} text The unmarked text.
 *
 * @returns {string} The marked text.
 */
export default function( text ) {
	// Strip the word boundaries at the start of the text.
	const strippedTextStart = stripWordBoundariesStart( text );
	let wordBoundaryStart = "";
	let wordBoundaryEnd = "";

	// Get the actual word boundaries from the start of the text.
	if ( strippedTextStart !== text ) {
		const wordBoundaryStartIndex = text.search( escapeRegExp( strippedTextStart ) );
		wordBoundaryStart = text.substr( 0, wordBoundaryStartIndex );
	}

	// Strip word boundaries at the end of the text.
	const strippedTextEnd = stripWordBoundariesEnd( strippedTextStart );
	// Get the actual word boundaries from the end of the text.
	if ( strippedTextEnd !== strippedTextStart ) {
		const wordBoundaryEndIndex = strippedTextStart.search( escapeRegExp( strippedTextEnd ) ) + strippedTextEnd.length;
		wordBoundaryEnd = strippedTextStart.substr( wordBoundaryEndIndex );
	}

	return wordBoundaryStart + "<yoastmark class='yoast-text-mark'>" + strippedTextEnd + "</yoastmark>" + wordBoundaryEnd;
}