Type Utilities II

Requirements

• Export isArray, isFunction, isObject, and isPlainObject. Each accepts any value and returns a boolean.
• isArray recognizes normal and sparse arrays. isFunction recognizes regular, arrow, async, generator, and class functions.
• isObject accepts every non-null object and every function, including arrays, dates, maps, sets, and boxed primitives. It rejects all primitive values and null.
• isPlainObject accepts an object whose immediate prototype is Object.prototype or null. Arrays, functions, class instances, dates, and objects with custom prototypes are not plain objects. Ignore any own property named constructor.
• Support values from the current JavaScript realm; cross-realm plain-object detection and revoked proxies are outside scope. Built-in type inspection APIs are allowed. Do not mutate input.

Examples

Input: isArray([]); isFunction(() => {});
Output: true; true

Input: isObject(null); isObject(() => {});
Output: false; true

Input: isPlainObject(Object.create(null)); isPlainObject(new Date());
Output: true; false