Google Tag Manager loader for Vite

vite-google-tag-manager.js

/**
 * Google Tag Manager loader
 *
 * VITE_GTM_ID="GTM-XXXXX"
 * VITE_GTM_DL_NAME=dataLayer
 *
 * @see https://developers.google.com/tag-platform/tag-manager/web/datalayer
 */

// Skip adding <noscript> element

(function (win, doc) {
    var containerId = import.meta.env.VITE_GTM_ID;
    var dataLayerName = import.meta.env.VITE_GTM_DL_NAME;
    var gtmScript = doc.createElement("script");
    var gtmScriptUrl = new URL("https://www.googletagmanager.com/gtm.js");

    if (typeof containerId !== "string" || typeof dataLayerName !== "string") {
        return;
    }

    if (!Array.isArray(win[dataLayerName])) {
        win[dataLayerName] = [];
    }
    // Add 2 new items to data layer
    win[dataLayerName].push({
        "gtm.start": Date.now(),
        "event": "gtm.js"
    });

    gtmScriptUrl.searchParams.append("id", containerId);
    if (dataLayerName !== "dataLayer") {
        gtmScriptUrl.searchParams.append("l", dataLayerName);
    }
    gtmScript.async = true;
    gtmScript.src = gtmScriptUrl.toString();
    doc.head.appendChild(gtmScript);
}(window, document));