highlight method(case insensitive, escape, etc...)

highlight.js

export const escapeHtml = string => string.replace(/[&<>"'/`=]/g, s => ({
	"&": "&amp;",
	"<": "&lt;",
	">": "&gt;",
	"\"": "&quot;",
	"'": "&#39;",
	"/": "&#x2F;",
	"`": "&#x60;",
	"=": "&#x3D;",
})[s]);

export const unescapeHtml = string => string.replace(/&([a-z]+|#[0-9]+);/g, s => ({
	"amp": "&",
	"lt": "<",
	"gt": ">",
	"quot": "\"",
	"#39": "'",
	"#x2F": "/",
	"#x60": "`",
	"#x3D": "=",
})[s]);


/**
 * highlight.
 * @param text            origin text
 * @param keyword         target keyword
 * @param element         html element
 * @param clazz           class array
 * @param escape          is escape
 * @param caseInsensitive case
 * @returns {string}
 */
export const highlight = ({text = "", keyword = "", element = "strong", clazz = [], escape = false, caseInsensitive = false}) => {
	if (!text) return text;
	if (!keyword) return escape ? escapeHtml(text) : text;

	const regex = new RegExp(keyword, caseInsensitive ? "ig" : "g");
	const indices = [];
	let matched;

	while ((matched = regex.exec(text))) {
		indices.push(matched.index);
	}

	let idx = 0;
	let result = "";

	for (const startIndex of indices) {
		const other = text.substring(idx, startIndex);
		const matchedText = text.substring(startIndex, startIndex + keyword.length);

		result += `${escape ? escapeHtml(other) : other}<${element}${clazz.length === 0 ? "" : ` class="${clazz.join(" ")}"`}>${escape ? escapeHtml(matchedText) : matchedText}</${element}>`;
		idx = startIndex + keyword.length;
	}
	result += escape ? escapeHtml(text.substring(idx, text.length)) : text.substring(idx, text.length);

	return result;
};