fix: formatNumber does not return string if Infinity or NaN

Author: danielkaradachki

src/numbers/format-number.js

@@ -10,7 +10,7 @@ export default function formatNumber(number, format = NUMBER_PLACEHOLDER, locale
     }
 
     if (!isFinite(number)) {
-        return number;
+        return String(number);
     }
 
     const info = localeInfo(locale);

test/numbers.js

@@ -50,8 +50,9 @@ describe('formatNumber', () => {
         expect(formatNumber(undefined)).toEqual("");
     });
 
-    it('should return value if not finite value is passed', () => {
-        expect(formatNumber(Infinity)).toBe(Infinity);
+    it('should return value as string if not finite value is passed', () => {
+        expect(formatNumber(Infinity)).toBe(String(Infinity));
+        expect(formatNumber(NaN)).toBe(String(NaN));
         expect(formatNumber("foo")).toEqual("foo");
     });