Validate ID

validate_id.js

((libs) => {
  var promises = [];
  libs.forEach((src) => {
    promises.push(new Promise(resolve => {
      if (!document.querySelector(`[src="${src}"]`)) {
        const script = document.createElement("script");
        script.src = src;
        script.async = false;
        script.onload = () => {
          resolve();
        };
        document.head.appendChild(script);
      } else {
        resolve();
      }      
    }));    
  });

  function validateId(id) {
    if (id === undefined || id === "") return false;
    var num = parseFloat(id);
    return num > 0 && num.toString().indexOf(".") === -1;
  }

  return Promise.all(promises)
    .then(() => {
      expect(validateId()).toEqual(false);
      expect(validateId("")).toEqual(false);
      expect(validateId(-1)).toEqual(false);
      expect(validateId("1")).toEqual(true);
      expect(validateId(1)).toEqual(true);      
      console.log("All tests passed.");
    });
})([
  "https://wzrd.in/standalone/expect@latest"
]);