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

1 files changed, 247 insertions, 0 deletions

diff --git a/packages/cli/src/ui/utils/computeStats.test.ts b/packages/cli/src/ui/utils/computeStats.test.ts
new file mode 100644
index 00000000..0e32ffe2
--- /dev/null
+++ b/packages/cli/src/ui/utils/computeStats.test.ts
@@ -0,0 +1,247 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { describe, it, expect } from 'vitest';
+import {
+  calculateAverageLatency,
+  calculateCacheHitRate,
+  calculateErrorRate,
+  computeSessionStats,
+} from './computeStats.js';
+import { ModelMetrics, SessionMetrics } from '../contexts/SessionContext.js';
+
+describe('calculateErrorRate', () => {
+  it('should return 0 if totalRequests is 0', () => {
+    const metrics: ModelMetrics = {
+      api: { totalRequests: 0, totalErrors: 0, totalLatencyMs: 0 },
+      tokens: {
+        prompt: 0,
+        candidates: 0,
+        total: 0,
+        cached: 0,
+        thoughts: 0,
+        tool: 0,
+      },
+    };
+    expect(calculateErrorRate(metrics)).toBe(0);
+  });
+
+  it('should calculate the error rate correctly', () => {
+    const metrics: ModelMetrics = {
+      api: { totalRequests: 10, totalErrors: 2, totalLatencyMs: 0 },
+      tokens: {
+        prompt: 0,
+        candidates: 0,
+        total: 0,
+        cached: 0,
+        thoughts: 0,
+        tool: 0,
+      },
+    };
+    expect(calculateErrorRate(metrics)).toBe(20);
+  });
+});
+
+describe('calculateAverageLatency', () => {
+  it('should return 0 if totalRequests is 0', () => {
+    const metrics: ModelMetrics = {
+      api: { totalRequests: 0, totalErrors: 0, totalLatencyMs: 1000 },
+      tokens: {
+        prompt: 0,
+        candidates: 0,
+        total: 0,
+        cached: 0,
+        thoughts: 0,
+        tool: 0,
+      },
+    };
+    expect(calculateAverageLatency(metrics)).toBe(0);
+  });
+
+  it('should calculate the average latency correctly', () => {
+    const metrics: ModelMetrics = {
+      api: { totalRequests: 10, totalErrors: 0, totalLatencyMs: 1500 },
+      tokens: {
+        prompt: 0,
+        candidates: 0,
+        total: 0,
+        cached: 0,
+        thoughts: 0,
+        tool: 0,
+      },
+    };
+    expect(calculateAverageLatency(metrics)).toBe(150);
+  });
+});
+
+describe('calculateCacheHitRate', () => {
+  it('should return 0 if prompt tokens is 0', () => {
+    const metrics: ModelMetrics = {
+      api: { totalRequests: 0, totalErrors: 0, totalLatencyMs: 0 },
+      tokens: {
+        prompt: 0,
+        candidates: 0,
+        total: 0,
+        cached: 100,
+        thoughts: 0,
+        tool: 0,
+      },
+    };
+    expect(calculateCacheHitRate(metrics)).toBe(0);
+  });
+
+  it('should calculate the cache hit rate correctly', () => {
+    const metrics: ModelMetrics = {
+      api: { totalRequests: 0, totalErrors: 0, totalLatencyMs: 0 },
+      tokens: {
+        prompt: 200,
+        candidates: 0,
+        total: 0,
+        cached: 50,
+        thoughts: 0,
+        tool: 0,
+      },
+    };
+    expect(calculateCacheHitRate(metrics)).toBe(25);
+  });
+});
+
+describe('computeSessionStats', () => {
+  it('should return all zeros for initial empty metrics', () => {
+    const metrics: SessionMetrics = {
+      models: {},
+      tools: {
+        totalCalls: 0,
+        totalSuccess: 0,
+        totalFail: 0,
+        totalDurationMs: 0,
+        totalDecisions: { accept: 0, reject: 0, modify: 0 },
+        byName: {},
+      },
+    };
+
+    const result = computeSessionStats(metrics);
+
+    expect(result).toEqual({
+      totalApiTime: 0,
+      totalToolTime: 0,
+      agentActiveTime: 0,
+      apiTimePercent: 0,
+      toolTimePercent: 0,
+      cacheEfficiency: 0,
+      totalDecisions: 0,
+      successRate: 0,
+      agreementRate: 0,
+      totalPromptTokens: 0,
+      totalCachedTokens: 0,
+    });
+  });
+
+  it('should correctly calculate API and tool time percentages', () => {
+    const metrics: SessionMetrics = {
+      models: {
+        'gemini-pro': {
+          api: { totalRequests: 1, totalErrors: 0, totalLatencyMs: 750 },
+          tokens: {
+            prompt: 10,
+            candidates: 10,
+            total: 20,
+            cached: 0,
+            thoughts: 0,
+            tool: 0,
+          },
+        },
+      },
+      tools: {
+        totalCalls: 1,
+        totalSuccess: 1,
+        totalFail: 0,
+        totalDurationMs: 250,
+        totalDecisions: { accept: 0, reject: 0, modify: 0 },
+        byName: {},
+      },
+    };
+
+    const result = computeSessionStats(metrics);
+
+    expect(result.totalApiTime).toBe(750);
+    expect(result.totalToolTime).toBe(250);
+    expect(result.agentActiveTime).toBe(1000);
+    expect(result.apiTimePercent).toBe(75);
+    expect(result.toolTimePercent).toBe(25);
+  });
+
+  it('should correctly calculate cache efficiency', () => {
+    const metrics: SessionMetrics = {
+      models: {
+        'gemini-pro': {
+          api: { totalRequests: 2, totalErrors: 0, totalLatencyMs: 1000 },
+          tokens: {
+            prompt: 150,
+            candidates: 10,
+            total: 160,
+            cached: 50,
+            thoughts: 0,
+            tool: 0,
+          },
+        },
+      },
+      tools: {
+        totalCalls: 0,
+        totalSuccess: 0,
+        totalFail: 0,
+        totalDurationMs: 0,
+        totalDecisions: { accept: 0, reject: 0, modify: 0 },
+        byName: {},
+      },
+    };
+
+    const result = computeSessionStats(metrics);
+
+    expect(result.cacheEfficiency).toBeCloseTo(33.33); // 50 / 150
+  });
+
+  it('should correctly calculate success and agreement rates', () => {
+    const metrics: SessionMetrics = {
+      models: {},
+      tools: {
+        totalCalls: 10,
+        totalSuccess: 8,
+        totalFail: 2,
+        totalDurationMs: 1000,
+        totalDecisions: { accept: 6, reject: 2, modify: 2 },
+        byName: {},
+      },
+    };
+
+    const result = computeSessionStats(metrics);
+
+    expect(result.successRate).toBe(80); // 8 / 10
+    expect(result.agreementRate).toBe(60); // 6 / 10
+  });
+
+  it('should handle division by zero gracefully', () => {
+    const metrics: SessionMetrics = {
+      models: {},
+      tools: {
+        totalCalls: 0,
+        totalSuccess: 0,
+        totalFail: 0,
+        totalDurationMs: 0,
+        totalDecisions: { accept: 0, reject: 0, modify: 0 },
+        byName: {},
+      },
+    };
+
+    const result = computeSessionStats(metrics);
+
+    expect(result.apiTimePercent).toBe(0);
+    expect(result.toolTimePercent).toBe(0);
+    expect(result.cacheEfficiency).toBe(0);
+    expect(result.successRate).toBe(0);
+    expect(result.agreementRate).toBe(0);
+  });
+});