update

src/utils/is.ts

@@ -0,0 +1,12 @@
+const objectToString = Object.prototype.toString;
+const toTypeString = (value: any) => objectToString.call(value);
+
+export const { isArray } = Array;
+export const isMap = (val: any) => toTypeString(val) === '[object Map]';
+export const isSet = (val: any) => toTypeString(val) === '[object Set]';
+export const isDate = (val: any) => val instanceof Date;
+export const isFunction = (val: any) => typeof val === 'function';
+export const isString = (val: any) => typeof val === 'string';
+export const isSymbol = (val: any) => typeof val === 'symbol';
+export const isObject = (val: null) => val !== null && typeof val === 'object';
+export const isPromise = (val: any) => isObject(val) && isFunction(val.then) && isFunction(val.catch);