test: browser environment assertion unit tests

Author: hejsztynx

src/web/__tests__/assertBrowserEnvironment.test.ts

@@ -0,0 +1,29 @@
+import { assertBrowserEnvironment } from '../assertBrowserEnvironment';
+
+describe('assertBrowserEnvironment', () => {
+  // jsdom provides a full DOM, so the browser APIs are present by default.
+  test('does not throw when the DOM globals are available', () => {
+    expect(() => assertBrowserEnvironment('EnrichedText')).not.toThrow();
+  });
+
+  // Each of these globals is required - removing any one should trip the assertion.
+  test.each(['window', 'document', 'DOMParser', 'Node'] as const)(
+    'throws when %s is missing',
+    (globalName) => {
+      // Simulate an SSR environment where each global is undefined.
+      const original = Object.getOwnPropertyDescriptor(globalThis, globalName);
+      Object.defineProperty(globalThis, globalName, {
+        value: undefined,
+        configurable: true,
+      });
+
+      try {
+        expect(() => assertBrowserEnvironment('EnrichedText')).toThrow(
+          /\[react-native-enriched\] EnrichedText is a client-only component/
+        );
+      } finally {
+        Object.defineProperty(globalThis, globalName, original!);
+      }
+    }
+  );
+});

src/web/assertBrowserEnvironment.ts

@@ -6,7 +6,13 @@
  * This asserts a DOM is available and throws a clear error otherwise.
  */
 export function assertBrowserEnvironment(componentName: string): void {
-  if (typeof window === 'undefined' || typeof document === 'undefined') {
+  const hasDOM =
+    typeof window !== 'undefined' &&
+    typeof document !== 'undefined' &&
+    typeof DOMParser !== 'undefined' &&
+    typeof Node !== 'undefined';
+
+  if (!hasDOM) {
     throw new Error(
       `[react-native-enriched] ${componentName} is a client-only component and cannot be rendered without a DOM. ` +
         `If you are running an SSR application, make sure the component is only rendered on the client.`