typeOf 1.0.0

/**
 * Gets the type of a value, as a name like `"Array"`, `"RegExp"` or
 * `"Promise"`. It goes further than `typeof`, which calls arrays, dates,
 * regular expressions and `null` all `"object"`.
 *
 * The name comes from, in order:
 *
 * - `"Null"` for `null` and `"Undefined"` for `undefined`.
 * - The name of the value's constructor. Instances of your own classes get
 *   the class's name (`"Person"`), and values from other frames or windows
 *   work too.
 * - The tag that `Object.prototype.toString()` gives (e.g. `"Object"` for
 *   objects made with `Object.create(null)`, which have no constructor).
 * - Its `typeof`, capitalized, if both of those throw (e.g. for a revoked
 *   `Proxy`).
 *
 * The constructor's name is trusted, so an object whose `constructor`
 * property is set to something else (`{constructor: Array}`) gets that name.
 *
 * @param {*} value
 *   The value whose type is wanted.
 * @returns {string}
 *   The type's name, starting with a capital letter.
 *
 * @example
 * typeOf([3, 6, 2]);          // "Array"
 * typeOf(/^[aeiou]/i);        // "RegExp"
 * typeOf(new Date());         // "Date"
 * typeOf(null);               // "Null"
 * typeOf(undefined);          // "Undefined"
 * typeOf(42);                 // "Number"
 * typeOf('hi');               // "String"
 * typeOf(10n);                // "BigInt"
 * typeOf(async () => {});     // "AsyncFunction"
 *
 * @example
 * // Instances of classes get the class's name
 * class Person {}
 * typeOf(new Person());       // "Person"
 *
 * // Objects without a constructor fall back to their tag
 * typeOf(Object.create(null)); // "Object"
 */
function typeOf(value) {
  if (value === null) return 'Null';
  if (value === undefined) return 'Undefined';

  try {
    const name = value.constructor?.name;
    if (typeof name === 'string' && name) return name;
  } catch { /* constructor lookup failed; fall back to toString */ }

  try {
    return Object.prototype.toString.call(value).slice(8, -1);
  }
  catch {
    const t = typeof value;
    return t[0].toUpperCase() + t.slice(1);
  }
}