feat(mcp): add progress bar, throttling, and input validation for MCP tool progress (#19772)

packages/cli/src/ui/components/messages/ToolShared.test.tsx

@@ -0,0 +1,72 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { describe, it, expect, vi } from 'vitest';
+import { render } from '../../../test-utils/render.js';
+import { Text } from 'ink';
+import { McpProgressIndicator } from './ToolShared.js';
+
+vi.mock('../GeminiRespondingSpinner.js', () => ({
+  GeminiRespondingSpinner: () => <Text>MockSpinner</Text>,
+}));
+
+describe('McpProgressIndicator', () => {
+  it('renders determinate progress at 50%', async () => {
+    const { lastFrame, waitUntilReady } = render(
+      <McpProgressIndicator progress={50} total={100} barWidth={20} />,
+    );
+    await waitUntilReady();
+    const output = lastFrame();
+    expect(output).toMatchSnapshot();
+    expect(output).toContain('50%');
+  });
+
+  it('renders complete progress at 100%', async () => {
+    const { lastFrame, waitUntilReady } = render(
+      <McpProgressIndicator progress={100} total={100} barWidth={20} />,
+    );
+    await waitUntilReady();
+    const output = lastFrame();
+    expect(output).toMatchSnapshot();
+    expect(output).toContain('100%');
+  });
+
+  it('renders indeterminate progress with raw count', async () => {
+    const { lastFrame, waitUntilReady } = render(
+      <McpProgressIndicator progress={7} barWidth={20} />,
+    );
+    await waitUntilReady();
+    const output = lastFrame();
+    expect(output).toMatchSnapshot();
+    expect(output).toContain('7');
+    expect(output).not.toContain('%');
+  });
+
+  it('renders progress with a message', async () => {
+    const { lastFrame, waitUntilReady } = render(
+      <McpProgressIndicator
+        progress={30}
+        total={100}
+        message="Downloading..."
+        barWidth={20}
+      />,
+    );
+    await waitUntilReady();
+    const output = lastFrame();
+    expect(output).toMatchSnapshot();
+    expect(output).toContain('Downloading...');
+  });
+
+  it('clamps progress exceeding total to 100%', async () => {
+    const { lastFrame, waitUntilReady } = render(
+      <McpProgressIndicator progress={150} total={100} barWidth={20} />,
+    );
+    await waitUntilReady();
+    const output = lastFrame();
+    expect(output).toContain('100%');
+    expect(output).not.toContain('150%');
+  });
+});