fix(ui5-date-picker): guard languageAware renders against in-flight language changes

packages/base/src/UI5Element.ts

@@ -898,6 +898,16 @@ abstract class UI5Element extends HTMLElement {
 	 */
 	_render() {
 		const ctor = this.constructor as typeof UI5Element;
+
+		// Skip rendering language-aware components while a language change (CLDR + i18n fetch) is
+		// still in flight. reRenderAllUI5Elements({ languageAware: true }) will re-render them once
+		// the data is ready. Without this guard, a component added to the render queue *before* the
+		// language change started (e.g. via renderDeferred) can still call onBeforeRendering and
+		// onAfterRendering with stale or missing locale data.
+		if (ctor.getMetadata().isLanguageAware() && getLanguageChangePending()) {
+			return;
+		}
+
 		const hasIndividualSlots = ctor.getMetadata().hasIndividualSlots();
 
 		// restore properties that were initialized before `define` by calling the setter

packages/main/cypress/specs/DatePicker.cy.tsx

@@ -4,7 +4,7 @@ import DatePicker from "../../src/DatePicker.js";
 import Label from "../../src/Label.js";
 import { DATEPICKER_POPOVER_ACCESSIBLE_NAME } from "../../src/generated/i18n/i18n-defaults.js";
 
-describe.skip("Date Picker Tests", () => {
+describe("Date Picker Tests", () => {
 	it("input renders", () => {
 		cy.mount(<DatePicker></DatePicker>);
 
@@ -34,7 +34,9 @@ describe.skip("Date Picker Tests", () => {
 
 	it("input receives value in format pattern depending on the set language", () => {
 		cy.wrap({ setLanguage })
-			.then(api => api.setLanguage("bg"));
+			.then(api => {
+				return api.setLanguage("bg");
+			});
 
 		cy.mount(<DatePicker value="11 декември 2018г." formatPattern="long"></DatePicker>);
 
@@ -58,7 +60,9 @@ describe.skip("Date Picker Tests", () => {
 			.should("have.class", "ui5-dp-item--selected");
 
 		cy.wrap({ setLanguage })
-			.then(api => api.setLanguage("en"));
+			.then(api => {
+				return api.setLanguage("en");
+			});
 	});
 
 	it("custom formatting", () => {
@@ -318,7 +322,9 @@ describe.skip("Date Picker Tests", () => {
 
 	it("respect first day of the week - monday", () => {
 		cy.wrap({ setLanguage })
-			.then(api => api.setLanguage("bg"));
+			.then(api => {
+				return api.setLanguage("bg");
+			});
 
 		cy.mount(<DatePicker value="фев 6, 2019" formatPattern="MMM d, y"></DatePicker>);
 
@@ -338,7 +344,9 @@ describe.skip("Date Picker Tests", () => {
 			.should("have.class", "ui5-dp-wday6");
 
 		cy.wrap({ setLanguage })
-			.then(api => api.setLanguage("en"));
+			.then(api => {
+				return api.setLanguage("en");
+			});
 	});
 
 	it("if today is 30 jan, clicking next month does not skip feb", () => {

packages/main/cypress/specs/DateRangePicker.cy.tsx

@@ -18,7 +18,9 @@ function DateRangePickerTemplate(options: DateTimePickerTemplateOptions) {
 
 describe("DateRangePicker general interaction", () => {
 	afterEach(() => {
-		cy.wrap({ setLanguage }).then(api => api.setLanguage("en"));
+		cy.wrap({ setLanguage }).then(api => {
+			return api.setLanguage("en");
+		});
 	});
 
 	it("Custom Validation Error", () => {