fix(jsx): log unmount errors instead of silently swallowing them

packages/jsx/src/render.ts

@@ -15,13 +15,17 @@ import { createElement } from './createElement.js';
 import { setCurrentApp } from './runtime.js';
 
 /**
- * Shared inline unmount helper — used by both the dev-server-backed path
- * and the fallback path so cleanup logic stays synchronized.
+ * Unmount a list of apps. Swallow any errors thrown by `unmount()` but log
+ * a single error message for observability. Exported only for tests.
  */
-function _unmountApps(apps: Array<{ unmount?: () => void }>): void {
+export function unmountApps(apps: Array<{ unmount?: () => void }>): void {
     apps.forEach((app) => {
         if (typeof app.unmount === 'function') {
-            try { app.unmount(); } catch {}
+            try {
+                app.unmount();
+            } catch (err) {
+                console.error('[jsx] Error during unmount():', err);
+            }
         }
     });
 }
@@ -162,7 +166,7 @@ export async function render(
                     // dev-server unavailable — use local helper for cleanup
                     const apps = (globalThis as any).__termuijs_apps;
                     if (Array.isArray(apps)) {
-                        _unmountApps(apps);
+                        unmountApps(apps);
                         (globalThis as any).__termuijs_apps = [];
                     }
                 });

packages/jsx/src/unmountHelpers.test.ts

@@ -0,0 +1,26 @@
+import { describe, it, expect, vi } from 'vitest';
+import { unmountApps } from './render.js';
+
+describe('unmountApps', () => {
+    it('logs errors, completes cleanup, and does not rethrow', () => {
+        const err = new Error('boom');
+        const throwing = { unmount: vi.fn(() => { throw err; }) };
+        const called = { unmount: vi.fn(() => { /* ok */ }) };
+
+        const spy = vi.spyOn(console, 'error').mockImplementation(() => {});
+
+        try {
+            // Should not throw
+            expect(() => unmountApps([throwing, called])).not.toThrow();
+
+            // Ensure the second unmount still ran
+            expect(called.unmount).toHaveBeenCalledTimes(1);
+
+            // Ensure we logged the error exactly once with the expected message
+            expect(spy).toHaveBeenCalledTimes(1);
+            expect(spy).toHaveBeenCalledWith('[jsx] Error during unmount():', err);
+        } finally {
+            spy.mockRestore();
+        }
+    });
+});