Re-enable reconnection failed invocation validation test.

- Relaxed the `maxRetries` and `retryIntervalMilliseconds` parameters to enable the test to complete quicker. Couldn't reproduce a failure even as the test is originally on my own Mac.

#12578

Author: N. Taylor Mullen

src/Components/Web.JS/tests/DefaultReconnectionHandler.test.ts

@@ -58,24 +58,23 @@ describe('DefaultReconnectionHandler', () => {
     expect(reconnect).toHaveBeenCalledTimes(1);
   });
 
-  // Skipped while under investigation: https://github.com/aspnet/AspNetCore/issues/12578
-  // it('invokes failed if reconnect fails', async () => {
-  //   const testDisplay = createTestDisplay();
-  //   const reconnect = jest.fn().mockRejectedValue(null);
-  //   const handler = new DefaultReconnectionHandler(NullLogger.instance, testDisplay, reconnect);
-  //   window.console.error = jest.fn();
-
-  //   handler.onConnectionDown({
-  //     maxRetries: 3,
-  //     retryIntervalMilliseconds: 20,
-  //     dialogId: 'ignored'
-  //   });
-
-  //   await delay(500);
-  //   expect(testDisplay.show).toHaveBeenCalled();
-  //   expect(testDisplay.failed).toHaveBeenCalled();
-  //   expect(reconnect).toHaveBeenCalledTimes(3);
-  // });
+  it('invokes failed if reconnect fails', async () => {
+    const testDisplay = createTestDisplay();
+    const reconnect = jest.fn().mockRejectedValue(null);
+    const handler = new DefaultReconnectionHandler(NullLogger.instance, testDisplay, reconnect);
+    window.console.error = jest.fn();
+
+    handler.onConnectionDown({
+      maxRetries: 2,
+      retryIntervalMilliseconds: 5,
+      dialogId: 'ignored'
+    });
+
+    await delay(500);
+    expect(testDisplay.show).toHaveBeenCalled();
+    expect(testDisplay.failed).toHaveBeenCalled();
+    expect(reconnect).toHaveBeenCalledTimes(2);
+  });
 });
 
 function attachUserSpecifiedUI(options: ReconnectionOptions): Element {