add a function to test if we have a safe opener

src/Umbraco.Web.UI.Client/src/packages/core/utils/index.ts

@@ -7,6 +7,7 @@ export * from './object/deep-merge.function.js';
 export * from './pagination-manager/pagination.manager.js';
 export * from './path/ensure-local-path.function.js';
 export * from './path/ensure-path-ends-with-slash.function.js';
+export * from './path/has-own-opener.function.js';
 export * from './path/path-decode.function.js';
 export * from './path/path-encode.function.js';
 export * from './path/path-folder-name.function.js';

src/Umbraco.Web.UI.Client/src/packages/core/utils/path/has-own-opener.function.test.ts

@@ -0,0 +1,64 @@
+import { expect } from '@open-wc/testing';
+import { hasOwnOpener } from './has-own-opener.function.js';
+
+describe('hasOwnOpener', () => {
+	// eslint-disable-next-line @typescript-eslint/no-explicit-any
+	let mockWindow: any;
+
+	beforeEach(() => {
+		mockWindow = {
+			location: {
+				origin: 'http://localhost',
+				pathname: '/test',
+			},
+		};
+	});
+
+	it('should return false if there is no opener', () => {
+		expect(hasOwnOpener(undefined, mockWindow)).to.be.false;
+	});
+
+	it('should return false if the opener is from a different origin', () => {
+		mockWindow.opener = {
+			location: {
+				origin: 'https://example.com',
+				pathname: '/test',
+			},
+		};
+
+		expect(hasOwnOpener(undefined, mockWindow)).to.be.false;
+	});
+
+	it('should return true if the opener is from the same origin and no pathname is specified', () => {
+		mockWindow.opener = {
+			location: {
+				origin: 'http://localhost',
+				pathname: '/test',
+			},
+		};
+
+		expect(hasOwnOpener(undefined, mockWindow)).to.be.true;
+	});
+
+	it('should return false if the opener is from the same origin but has a different pathname', () => {
+		mockWindow.opener = {
+			location: {
+				origin: 'http://localhost',
+				pathname: '/different',
+			},
+		};
+
+		expect(hasOwnOpener('/test', mockWindow)).to.be.false;
+	});
+
+	it('should return true if the opener is from the same origin and has the same pathname', () => {
+		mockWindow.opener = {
+			location: {
+				origin: 'http://localhost',
+				pathname: '/test',
+			},
+		};
+
+		expect(hasOwnOpener('/test', mockWindow)).to.be.true;
+	});
+});

src/Umbraco.Web.UI.Client/src/packages/core/utils/path/has-own-opener.function.ts

@@ -0,0 +1,35 @@
+/**
+ * Check if the current window has an opener window with the same origin and optional pathname.
+ * This is useful for checking if the current window was opened by another window from within the same application.
+ * @remark If the current window was opened by another window, the opener window is accessible via `window.opener`.
+ * @remark There could still be an opener if the opener window is closed or navigated away or if the opener window is not from the same origin,
+ * but this function will only return `true` if the opener window is accessible and has the same origin and optional pathname.
+ *
+ * @param pathname Optional pathname to check if the opener window has the same pathname.
+ * @param windowLike The window-like object to use for checking the opener. Default is `window`.
+ * @returns `true` if the current window has an opener window with the same origin and optional pathname, otherwise `false`.
+ */
+export function hasOwnOpener(pathname?: string, windowLike: Window = globalThis.window): boolean {
+	try {
+		const opener = windowLike.opener;
+		if (!opener) {
+			return false;
+		}
+
+		const openerLocation = opener.location;
+		const currentLocation = windowLike.location;
+
+		if (openerLocation.origin !== currentLocation.origin) {
+			return false;
+		}
+
+		if (pathname && openerLocation.pathname !== pathname) {
+			return false;
+		}
+
+		return true;
+	} catch (e) {
+		// If there is a security error, it means that the opener is from a different origin, so we let it fall through
+		return false;
+	}
+}