fix(types): fix TS type warnings

Author: ghiscoding-SE

src/app/modules/angular-slickgrid/services/__tests__/utilities.spec.ts

@@ -369,13 +369,6 @@ describe('Service/Utilies', () => {
       expect(output).toBe('(123.00)');
     });
 
-    it('should return a formatted string wrapped in parentheses when the input number is negative and the displayNegativeNumberWithParentheses argument is enabled', () => {
-      const input = -123;
-      const displayNegativeNumberWithParentheses = true;
-      const output = formatNumber(input, 2, 2, displayNegativeNumberWithParentheses);
-      expect(output).toBe('(123.00)');
-    });
-
     it('should return a formatted string and thousand separator wrapped in parentheses when the input number is negative and the displayNegativeNumberWithParentheses argument is enabled', () => {
       const input = -12345678;
       const displayNegativeNumberWithParentheses = true;

src/app/modules/angular-slickgrid/services/utilities.ts

@@ -208,7 +208,7 @@ export function decimalFormatted(input: number | string, minDecimal?: number, ma
   let output = '';
   if (integerNumber !== undefined && decimalNumber !== undefined) {
     output = `${integerNumber}${decimalSeparator}${decimalNumber}`;
-  } else {
+  } else if (integerNumber !== undefined && integerNumber !== null) {
     output = integerNumber;
   }
   return output;