Fix FormulaWidget column check (#437)

CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ## Not released
 
+- Fix FormulaWidget column check [#437](https://github.com/CartoDB/carto-react/pull/437)
+
 ## 1.3
 
 ### 1.3.0-beta.2 (2022-06-20)

packages/react-widgets/src/widgets/utils/propTypesFns.js

@@ -20,18 +20,20 @@ export const checkFormulaColumn = (props, propName) => {
   const isValidString = !!propValue && typeof propValue === 'string';
   const isValidArray = Array.isArray(propValue) && propValue.length;
 
+  const isValid = isValidString || isValidArray;
+
   const validationError = new Error(`Prop ${propName} must be a string or an array`);
 
   if (props.operation === AggregationTypes.COUNT) {
-    if (propValue && !(isValidString || isValidArray)) {
+    if (propValue && !isValid) {
       return validationError;
     }
   } else {
     if (!propValue) {
       return new Error(`Prop ${propName} must be defined`);
     }
 
-    if (!isValidArray || !isValidString) {
+    if (!isValid) {
       return validationError;
     }
   }