Add check for null when formatting value

@@ -123,16 +123,16 @@ export function isEmpty(obj: any): boolean {
 }
 
 export function formatValue(value: any, dec?: number, units?: string, showZeroDecimals?: boolean): string | undefined {
-  if (isDefinedAndNotNull(value) && isNumeric(value) && (isDefined(dec) || isDefined(units) || Number(value).toString() === value)) {
+  if (isDefinedAndNotNull(value) && isNumeric(value) && (isDefinedAndNotNull(dec) || isDefinedAndNotNull(units) || Number(value).toString() === value)) {
     let formatted: string | number = Number(value);
-    if (isDefined(dec)) {
+    if (isDefinedAndNotNull(dec)) {
       formatted = formatted.toFixed(dec);
     }
     if (!showZeroDecimals) {
       formatted = (Number(formatted));
     }
     formatted = formatted.toString();
-    if (isDefined(units) && units.length > 0) {
+    if (isDefinedAndNotNull(units) && units.length > 0) {
       formatted += ' ' + units;
     }
     return formatted;