feat: Change /stats to include more detailed breakdowns (#2615)

packages/cli/src/ui/components/ToolStatsDisplay.test.tsx

@@ -0,0 +1,176 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { render } from 'ink-testing-library';
+import { describe, it, expect, vi } from 'vitest';
+import { ToolStatsDisplay } from './ToolStatsDisplay.js';
+import * as SessionContext from '../contexts/SessionContext.js';
+import { SessionMetrics } from '../contexts/SessionContext.js';
+
+// Mock the context to provide controlled data for testing
+vi.mock('../contexts/SessionContext.js', async (importOriginal) => {
+  const actual = await importOriginal<typeof SessionContext>();
+  return {
+    ...actual,
+    useSessionStats: vi.fn(),
+  };
+});
+
+const useSessionStatsMock = vi.mocked(SessionContext.useSessionStats);
+
+const renderWithMockedStats = (metrics: SessionMetrics) => {
+  useSessionStatsMock.mockReturnValue({
+    stats: {
+      sessionStartTime: new Date(),
+      metrics,
+      lastPromptTokenCount: 0,
+    },
+  });
+
+  return render(<ToolStatsDisplay />);
+};
+
+describe('<ToolStatsDisplay />', () => {
+  it('should render "no tool calls" message when there are no active tools', () => {
+    const { lastFrame } = renderWithMockedStats({
+      models: {},
+      tools: {
+        totalCalls: 0,
+        totalSuccess: 0,
+        totalFail: 0,
+        totalDurationMs: 0,
+        totalDecisions: { accept: 0, reject: 0, modify: 0 },
+        byName: {},
+      },
+    });
+
+    expect(lastFrame()).toContain(
+      'No tool calls have been made in this session.',
+    );
+    expect(lastFrame()).toMatchSnapshot();
+  });
+
+  it('should display stats for a single tool correctly', () => {
+    const { lastFrame } = renderWithMockedStats({
+      models: {},
+      tools: {
+        totalCalls: 1,
+        totalSuccess: 1,
+        totalFail: 0,
+        totalDurationMs: 100,
+        totalDecisions: { accept: 1, reject: 0, modify: 0 },
+        byName: {
+          'test-tool': {
+            count: 1,
+            success: 1,
+            fail: 0,
+            durationMs: 100,
+            decisions: { accept: 1, reject: 0, modify: 0 },
+          },
+        },
+      },
+    });
+
+    const output = lastFrame();
+    expect(output).toContain('test-tool');
+    expect(output).toMatchSnapshot();
+  });
+
+  it('should display stats for multiple tools correctly', () => {
+    const { lastFrame } = renderWithMockedStats({
+      models: {},
+      tools: {
+        totalCalls: 3,
+        totalSuccess: 2,
+        totalFail: 1,
+        totalDurationMs: 300,
+        totalDecisions: { accept: 1, reject: 1, modify: 1 },
+        byName: {
+          'tool-a': {
+            count: 2,
+            success: 1,
+            fail: 1,
+            durationMs: 200,
+            decisions: { accept: 1, reject: 1, modify: 0 },
+          },
+          'tool-b': {
+            count: 1,
+            success: 1,
+            fail: 0,
+            durationMs: 100,
+            decisions: { accept: 0, reject: 0, modify: 1 },
+          },
+        },
+      },
+    });
+
+    const output = lastFrame();
+    expect(output).toContain('tool-a');
+    expect(output).toContain('tool-b');
+    expect(output).toMatchSnapshot();
+  });
+
+  it('should handle large values without wrapping or overlapping', () => {
+    const { lastFrame } = renderWithMockedStats({
+      models: {},
+      tools: {
+        totalCalls: 999999999,
+        totalSuccess: 888888888,
+        totalFail: 111111111,
+        totalDurationMs: 987654321,
+        totalDecisions: {
+          accept: 123456789,
+          reject: 98765432,
+          modify: 12345,
+        },
+        byName: {
+          'long-named-tool-for-testing-wrapping-and-such': {
+            count: 999999999,
+            success: 888888888,
+            fail: 111111111,
+            durationMs: 987654321,
+            decisions: {
+              accept: 123456789,
+              reject: 98765432,
+              modify: 12345,
+            },
+          },
+        },
+      },
+    });
+
+    expect(lastFrame()).toMatchSnapshot();
+  });
+
+  it('should handle zero decisions gracefully', () => {
+    const { lastFrame } = renderWithMockedStats({
+      models: {},
+      tools: {
+        totalCalls: 1,
+        totalSuccess: 1,
+        totalFail: 0,
+        totalDurationMs: 100,
+        totalDecisions: { accept: 0, reject: 0, modify: 0 },
+        byName: {
+          'test-tool': {
+            count: 1,
+            success: 1,
+            fail: 0,
+            durationMs: 100,
+            decisions: { accept: 0, reject: 0, modify: 0 },
+          },
+        },
+      },
+    });
+
+    const output = lastFrame();
+    expect(output).toContain('Total Reviewed Suggestions:');
+    expect(output).toContain('0');
+    expect(output).toContain('Overall Agreement Rate:');
+    expect(output).toContain('--');
+    expect(output).toMatchSnapshot();
+  });
+});