HTMLScriptElement: supports()

HTMLScriptElement.supports(type)

const log = document.getElementById("log");

function checkSupport(type) {
  const result = HTMLScriptElement.supports(type) ? "true" : "false";
  log.textContent += `HTMLScriptElement.supports('${type}')  ${result}\n`;
}

if (typeof HTMLScriptElement.supports === "undefined") {
  log.textContent = "HTMLScriptElement.supports() ";
} else {
  // 
  checkSupport("module");
  checkSupport("classic");
  checkSupport("importmap");
  checkSupport("speculationrules");
  //  false 
  checkSupport("anything else");
}

<textarea id="log" rows="6" cols="80"></textarea>