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

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

@@ -0,0 +1,235 @@
+/**
+ * @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 { ModelStatsDisplay } from './ModelStatsDisplay.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(<ModelStatsDisplay />);
+};
+
+describe('<ModelStatsDisplay />', () => {
+  it('should render "no API calls" message when there are no active models', () => {
+    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 API calls have been made in this session.',
+    );
+    expect(lastFrame()).toMatchSnapshot();
+  });
+
+  it('should not display conditional rows if no model has data for them', () => {
+    const { lastFrame } = renderWithMockedStats({
+      models: {
+        'gemini-2.5-pro': {
+          api: { totalRequests: 1, totalErrors: 0, totalLatencyMs: 100 },
+          tokens: {
+            prompt: 10,
+            candidates: 20,
+            total: 30,
+            cached: 0,
+            thoughts: 0,
+            tool: 0,
+          },
+        },
+      },
+      tools: {
+        totalCalls: 0,
+        totalSuccess: 0,
+        totalFail: 0,
+        totalDurationMs: 0,
+        totalDecisions: { accept: 0, reject: 0, modify: 0 },
+        byName: {},
+      },
+    });
+
+    const output = lastFrame();
+    expect(output).not.toContain('Cached');
+    expect(output).not.toContain('Thoughts');
+    expect(output).not.toContain('Tool');
+    expect(output).toMatchSnapshot();
+  });
+
+  it('should display conditional rows if at least one model has data', () => {
+    const { lastFrame } = renderWithMockedStats({
+      models: {
+        'gemini-2.5-pro': {
+          api: { totalRequests: 1, totalErrors: 0, totalLatencyMs: 100 },
+          tokens: {
+            prompt: 10,
+            candidates: 20,
+            total: 30,
+            cached: 5,
+            thoughts: 2,
+            tool: 0,
+          },
+        },
+        'gemini-2.5-flash': {
+          api: { totalRequests: 1, totalErrors: 0, totalLatencyMs: 50 },
+          tokens: {
+            prompt: 5,
+            candidates: 10,
+            total: 15,
+            cached: 0,
+            thoughts: 0,
+            tool: 3,
+          },
+        },
+      },
+      tools: {
+        totalCalls: 0,
+        totalSuccess: 0,
+        totalFail: 0,
+        totalDurationMs: 0,
+        totalDecisions: { accept: 0, reject: 0, modify: 0 },
+        byName: {},
+      },
+    });
+
+    const output = lastFrame();
+    expect(output).toContain('Cached');
+    expect(output).toContain('Thoughts');
+    expect(output).toContain('Tool');
+    expect(output).toMatchSnapshot();
+  });
+
+  it('should display stats for multiple models correctly', () => {
+    const { lastFrame } = renderWithMockedStats({
+      models: {
+        'gemini-2.5-pro': {
+          api: { totalRequests: 10, totalErrors: 1, totalLatencyMs: 1000 },
+          tokens: {
+            prompt: 100,
+            candidates: 200,
+            total: 300,
+            cached: 50,
+            thoughts: 10,
+            tool: 5,
+          },
+        },
+        'gemini-2.5-flash': {
+          api: { totalRequests: 20, totalErrors: 2, totalLatencyMs: 500 },
+          tokens: {
+            prompt: 200,
+            candidates: 400,
+            total: 600,
+            cached: 100,
+            thoughts: 20,
+            tool: 10,
+          },
+        },
+      },
+      tools: {
+        totalCalls: 0,
+        totalSuccess: 0,
+        totalFail: 0,
+        totalDurationMs: 0,
+        totalDecisions: { accept: 0, reject: 0, modify: 0 },
+        byName: {},
+      },
+    });
+
+    const output = lastFrame();
+    expect(output).toContain('gemini-2.5-pro');
+    expect(output).toContain('gemini-2.5-flash');
+    expect(output).toMatchSnapshot();
+  });
+
+  it('should handle large values without wrapping or overlapping', () => {
+    const { lastFrame } = renderWithMockedStats({
+      models: {
+        'gemini-2.5-pro': {
+          api: {
+            totalRequests: 999999999,
+            totalErrors: 123456789,
+            totalLatencyMs: 9876,
+          },
+          tokens: {
+            prompt: 987654321,
+            candidates: 123456789,
+            total: 999999999,
+            cached: 123456789,
+            thoughts: 111111111,
+            tool: 222222222,
+          },
+        },
+      },
+      tools: {
+        totalCalls: 0,
+        totalSuccess: 0,
+        totalFail: 0,
+        totalDurationMs: 0,
+        totalDecisions: { accept: 0, reject: 0, modify: 0 },
+        byName: {},
+      },
+    });
+
+    expect(lastFrame()).toMatchSnapshot();
+  });
+
+  it('should display a single model correctly', () => {
+    const { lastFrame } = renderWithMockedStats({
+      models: {
+        'gemini-2.5-pro': {
+          api: { totalRequests: 1, totalErrors: 0, totalLatencyMs: 100 },
+          tokens: {
+            prompt: 10,
+            candidates: 20,
+            total: 30,
+            cached: 5,
+            thoughts: 2,
+            tool: 1,
+          },
+        },
+      },
+      tools: {
+        totalCalls: 0,
+        totalSuccess: 0,
+        totalFail: 0,
+        totalDurationMs: 0,
+        totalDecisions: { accept: 0, reject: 0, modify: 0 },
+        byName: {},
+      },
+    });
+
+    const output = lastFrame();
+    expect(output).toContain('gemini-2.5-pro');
+    expect(output).not.toContain('gemini-2.5-flash');
+    expect(output).toMatchSnapshot();
+  });
+});