<pre class="shiki github-dark shaku"><code>// enable myCookiefunction install() { // A "private" variable to store our cookies document._myCookie = {}; Object.defineProperty(document, "myCookie", { get() { return Object.entries(this._myCookie) .map(([k,v]) =&gt; `${k}=${v}`) .join("; "); }, set(val) { // Get all key-value pairs, trimming strings in each step const keyValuePairs = val.split(";") .map(pair =&gt; pair.trim()) .filter(pair =&gt; pair.length &gt; 0) .map(pair =&gt; { const [k,v] = pair.split("="); return [k.trim(), v.trim()]; }) const [cookieName, cookieValue] = keyValuePairs[0]; const [,maxAgeStr] = keyValuePairs[1] || []; const maxAge = maxAgeStr &amp;&amp; maxAgeStr.length ? parseInt(maxAgeStr) : null; // Store it only if maxAge is absent or if it's greater than 0 if (maxAge == null || maxAge &gt; 0) { document._myCookie[cookieName] = cookieValue; } if (maxAge) { // Set a timer to delete the cookie after maxAge setTimeout(() =&gt; { if (document._myCookie) { delete document._myCookie[cookieName]; } }, maxAge * 1000); } }, // We want to be able to delete the property later configurable: true, });}// disable myCookiefunction uninstall() { delete document.myCookie; delete document._myCookie;}</code></pre>

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We can get and set cookie by document.cookie. document.cookie = 'bfe=dev'// "bfe=dev"document.cookie = 'bfe1=dev1'// "bfe1=dev1"document.cookie// "bfe…