Highlight Search match in JS

javascript-highlight-text.js

function highlightMatch(string, regexp) {
  return escapeString(string).replace(regexp, (match) => `<mark>${match}</mark>`)
}

// Used to match HTML entities and HTML characters.
const unescapedHtml = /[&<>"']/g
const hasUnescapedHtml = RegExp(unescapedHtml.source)
const htmlEscapes = {
  '&': '&amp;',
  '<': '&lt;',
  '>': '&gt;',
  '"': '&quot;',
  "'": '&#39;',
}

/* Converts the characters "&", "<", ">", '"', & "'" in `string` to their corresponding HTML entities */
function escapeString(str) {
  return str && hasUnescapedHtml.test(str) ? str.replace(unescapedHtml, character => htmlEscapes[character]) : str;
}

const content = `Lorem ipsum dolor sit amet, consectetur adipiscing elit. 
Integer vitae mauris arcu, eu pretium nisi. Praesent fringilla ornare ullamcorper. 
Pellentesque diam orci, sodales in blandit ut, placerat quis felis. 
Vestibulum at sem massa, in tempus nisi. Vivamus ut fermentum odio. Etiam porttitor faucibus volutpat. 
Vivamus vitae mi ligula, non hendrerit urna. Suspendisse potenti. Quisque eget massa a massa semper mollis.`

const searchWord = 'orci'
console.log(highlightMatch(content, new RegExp(searchWord, "gi")))
/*
Lorem ipsum dolor sit amet, consectetur adipiscing elit. 
Integer vitae mauris arcu, eu pretium nisi. Praesent fringilla ornare ullamcorper. 
Pellentesque diam <mark>orci</mark>, sodales in blandit ut, placerat quis felis. 
Vestibulum at sem massa, in tempus nisi. Vivamus ut fermentum odio. Etiam porttitor faucibus volutpat. 
Vivamus vitae mi ligula, non hendrerit urna. Suspendisse potenti. Quisque eget massa a massa semper mollis.
*/