chore(util): add isPrimitive() util

src/util/test/util.spec.ts

@@ -2,6 +2,39 @@ import * as util from '../../../src/util';
 
 export function run() {
 
+  describe('isPrimitive', () => {
+
+    it('should be false for array/object values', () => {
+      expect(util.isPrimitive({})).toEqual(false);
+      expect(util.isPrimitive(new Date())).toEqual(false);
+      expect(util.isPrimitive([])).toEqual(false);
+    });
+
+    it('should be false for blank values', () => {
+      expect(util.isPrimitive(NaN)).toEqual(false);
+      expect(util.isPrimitive(null)).toEqual(false);
+      expect(util.isPrimitive(undefined)).toEqual(false);
+    });
+
+    it('should be true for number', () => {
+      expect(util.isPrimitive(-1)).toEqual(true);
+      expect(util.isPrimitive(0)).toEqual(true);
+      expect(util.isPrimitive(1)).toEqual(true);
+    });
+
+    it('should be true for boolean', () => {
+      expect(util.isPrimitive(true)).toEqual(true);
+      expect(util.isPrimitive(false)).toEqual(true);
+    });
+
+    it('should be true for string', () => {
+      expect(util.isPrimitive('')).toEqual(true);
+      expect(util.isPrimitive('   ')).toEqual(true);
+      expect(util.isPrimitive('hi')).toEqual(true);
+    });
+
+  });
+
   describe('isCheckedProperty', () => {
 
     it('should test a=undefined', () => {

src/util/util.ts

@@ -111,6 +111,10 @@ export const isBlank = (val: any) => val === undefined || val === null;
 export const isObject = (val: any) => typeof val === 'object';
 export const isArray = Array.isArray;
 
+export const isPrimitive = function(val: any) {
+  return isString(val) || isBoolean(val) || (isNumber(val) && !isNaN(val));
+};
+
 export const isTrueProperty = function(val: any): boolean {
   if (typeof val === 'string') {
     val = val.toLowerCase().trim();