jenis/functions.js

Data type checker utility

const functions = {
    isString: object => typeof object === 'string' || object instanceof String,
    isArray: object => object && typeof object === 'object' && object.constructor === Array,
    isObject: object => object && typeof object === 'object' && object.constructor === Object,
    isNumber: object => typeof object === 'number' && isFinite(object),
    isFunction: object => typeof object === 'function',
    isNull: object => object === null,
    isUndefined: object => typeof object === 'undefined',
    isBoolean: object => typeof object === 'boolean',
    isRegExp: object => object && typeof object === 'object' && object.constructor === RegExp,
    isError: object => object instanceof Error && typeof object.message !== 'undefined',
    isDate: object => object instanceof Date,
    isSymbol: object => typeof object === 'symbol',
    isPromise: object => Object.prototype.toString.call(object) == 'promise' && object instanceof Promise,
    check: object => {
        switch (typeof object) {
			case "number": return "number"
			case "string": return "string"
			case "boolean": return "boolean"
			case "undefined": return "undefined"
			case "function": return "function"
			case "symbol": return "symbol"
			case "object":
			default:
				switch (Object.prototype.toString.call(object)) {
					case "[object Number]": return "number"
					case "[object String]": return "string"
					case "[object Boolean]": return "boolean"
					case "[object Undefined]": return "undefined"
					case "[object Null]": return "null"
					case "[object Function]": return "function"
					case "[object Array]": return "array"
					case "[object Symbol]": return "symbolin"
					case "[object Promise]": return "promise"
					case "[object Error]": return "error"
					case "[object RegExp]": return "regexp"
					case "[object Date]": return "date"
					default: 
						if ( typeof Array !== "undefined" && object instanceof Array) return "array"
						if ( typeof Function !== "undefined" && object instanceof Function) return "function"
						if ( typeof Promise !== "undefined" && object instanceof Promise) return "promise"
						if ( typeof Error !== "undefined" && object instanceof Error) return "error"
						if ( typeof RegExp !== "undefined" && object instanceof RegExp) return "regexp"
						if ( typeof Date !== "undefined" && object instanceof Date) return "date"
				}
		}
		return "object"
    },
}

module.exports = functions