fix: inflate functions in arrays (#5646)

* fix: inflate functions in arrays

* refactor: handle arrays in separate blocks for clarification

packages/charts/src/helpers.js

@@ -1,8 +1,12 @@
 export function inflateFunctions(config) {
+  if (Array.isArray(config)) {
+    config.forEach(inflateFunctions);
+    return;
+  }
   if (
     // Check if param is a primitive/null/undefined value
     !(config instanceof Object) ||
-    // Check if param is a plain object (not an array or HC object)
+    // Check if param is a plain object (not a HC object)
     config.constructor !== Object
   ) {
     return;

packages/charts/test/private-api.test.js

@@ -29,6 +29,16 @@ describe('vaadin-chart private API', () => {
       expect(config.tooltip).to.not.have.property('_fn_formatter');
     });
 
+    it('should inflate function strings in array', () => {
+      const exportFunction = 'function () {this.exportChart();}';
+      // eslint-disable-next-line camelcase
+      const config = { exporting: { buttons: { contextButton: { menuItems: [{ _fn_onclick: exportFunction }] } } } };
+      inflateFunctions(config);
+      const exportButton = config.exporting.buttons.contextButton.menuItems[0];
+      expect(exportButton.onclick.toString()).to.be.equal(exportFunction);
+      expect(exportButton).to.not.have.property('_fn_onclick');
+    });
+
     it('should not try to inflate if a non-object value is passed', () => {
       // Check for no errors being thrown
       inflateFunctions(null);