fix: Auto-dismiss success snackbars for signal workflow buttons (#1231)

## Summary

- Success notifications from signal buttons in markdown query results
now auto-dismiss after 5 seconds (`DURATION.medium`) instead of
persisting indefinitely
- Error notifications remain persistent and require manual dismissal
- Added tests for signal button snackbar behavior

## What changed

When clicking signal buttons in markdown query results, success
snackbars previously required manual dismissal via the "OK" button. This
caused snackbars to stack up when triggering multiple signals in
succession, and they persisted even when navigating away from the page.

Now, success notifications auto-dismiss after 5 seconds using baseui's
`DURATION.medium` constant, passed as the second argument to
`enqueue()`. Error notifications are unaffected and still require manual
dismissal to ensure users notice failures.

## Test plan

- [x] Added unit tests for `SignalButton` component covering:
  - Button rendering and disabled state
  - Success snackbar fires with `DURATION.medium` (5000ms) auto-dismiss
- Error snackbar fires without a duration (uses provider default:
infinite)
- [x] Verified existing markdown tests still pass
- [x] Linting passes with no warnings or errors

Closes #1219

Signed-off-by: Asish Kumar <officialasishkumar@gmail.com>
Co-authored-by: Adhitya Mamallan <adhitya.mamallan@uber.com>

Author: officialasishkumar

src/components/markdown/markdoc-components/signal-button/__tests__/signal-button.test.tsx

@@ -0,0 +1,116 @@
+import { HttpResponse } from 'msw';
+
+import { render, screen, userEvent, waitFor } from '@/test-utils/rtl';
+
+import SignalButton from '../signal-button';
+import { SIGNAL_SUCCESS_NOTIFICATION_DURATION_MS } from '../signal-button.constants';
+
+const mockEnqueue = jest.fn();
+jest.mock('baseui/snackbar', () => ({
+  ...jest.requireActual('baseui/snackbar'),
+  useSnackbar: () => ({
+    enqueue: mockEnqueue,
+    dequeue: jest.fn(),
+  }),
+}));
+
+const SIGNAL_ENDPOINT =
+  '/api/domains/:domain/:cluster/workflows/:workflowId/:runId/signal';
+
+const defaultProps = {
+  signalName: 'test-signal',
+  label: 'Send Signal',
+  domain: 'test-domain',
+  cluster: 'test-cluster',
+  workflowId: 'test-workflow-id',
+  runId: 'test-run-id',
+};
+
+describe(SignalButton.name, () => {
+  beforeEach(() => {
+    jest.clearAllMocks();
+  });
+
+  it('renders the button with the provided label', () => {
+    setup({});
+
+    expect(
+      screen.getByRole('button', { name: 'Send Signal' })
+    ).toBeInTheDocument();
+  });
+
+  it('disables the button when required props are missing', () => {
+    setup({ propsOverrides: { domain: undefined } });
+
+    expect(screen.getByRole('button', { name: 'Send Signal' })).toHaveAttribute(
+      'disabled'
+    );
+  });
+
+  it('shows a success snackbar with auto-dismiss duration after signaling', async () => {
+    const { user } = setup({});
+
+    const button = screen.getByRole('button', { name: 'Send Signal' });
+    await user.click(button);
+
+    await waitFor(() => {
+      expect(mockEnqueue).toHaveBeenCalledWith(
+        expect.objectContaining({
+          message: 'Successfully sent signal "test-signal"',
+          actionMessage: 'OK',
+        }),
+        SIGNAL_SUCCESS_NOTIFICATION_DURATION_MS
+      );
+    });
+  });
+
+  it('shows an error snackbar without auto-dismiss duration on failure', async () => {
+    const { user } = setup({ error: true });
+
+    const button = screen.getByRole('button', { name: 'Send Signal' });
+    await user.click(button);
+
+    await waitFor(() => {
+      expect(mockEnqueue).toHaveBeenCalledWith(
+        expect.objectContaining({
+          actionMessage: 'Dismiss',
+        })
+      );
+    });
+
+    // Error snackbar should not pass a duration (uses provider default: infinite)
+    expect(mockEnqueue).toHaveBeenCalledTimes(1);
+    expect(mockEnqueue.mock.calls[0]).toHaveLength(1);
+  });
+});
+
+function setup({
+  error,
+  propsOverrides,
+}: {
+  error?: boolean;
+  propsOverrides?: Partial<typeof defaultProps>;
+}) {
+  const user = userEvent.setup();
+
+  render(<SignalButton {...defaultProps} {...propsOverrides} />, {
+    endpointsMocks: [
+      {
+        path: SIGNAL_ENDPOINT,
+        httpMethod: 'POST',
+        mockOnce: false,
+        httpResolver: async () => {
+          if (error) {
+            return HttpResponse.json(
+              { message: 'Failed to signal workflow' },
+              { status: 500 }
+            );
+          }
+          return HttpResponse.json({});
+        },
+      },
+    ],
+  });
+
+  return { user };
+}

src/components/markdown/markdoc-components/signal-button/signal-button.constants.ts

@@ -0,0 +1 @@
+export const SIGNAL_SUCCESS_NOTIFICATION_DURATION_MS = 5000;

src/components/markdown/markdoc-components/signal-button/signal-button.tsx

@@ -6,6 +6,7 @@ import { useSnackbar } from 'baseui/snackbar';
 import losslessJsonStringify from '@/utils/lossless-json-stringify';
 import request from '@/utils/request';
 
+import { SIGNAL_SUCCESS_NOTIFICATION_DURATION_MS } from './signal-button.constants';
 import { overrides } from './signal-button.styles';
 import { type SignalButtonProps } from './signal-button.types';
 
@@ -45,10 +46,13 @@ export default function SignalButton({
       return response.json();
     },
     onSuccess: () => {
-      enqueue({
-        message: `Successfully sent signal "${signalName}"`,
-        actionMessage: 'OK',
-      });
+      enqueue(
+        {
+          message: `Successfully sent signal "${signalName}"`,
+          actionMessage: 'OK',
+        },
+        SIGNAL_SUCCESS_NOTIFICATION_DURATION_MS
+      );
     },
     onError: (error: Error) => {
       enqueue({