Emit a warning when memory usage exceeds 7GB (#7613)

packages/cli/src/ui/hooks/useMemoryMonitor.test.ts

@@ -0,0 +1,71 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { renderHook } from '@testing-library/react';
+import { vi } from 'vitest';
+import {
+  useMemoryMonitor,
+  MEMORY_CHECK_INTERVAL,
+  MEMORY_WARNING_THRESHOLD,
+} from './useMemoryMonitor.js';
+import process from 'node:process';
+import { MessageType } from '../types.js';
+
+describe('useMemoryMonitor', () => {
+  const memoryUsageSpy = vi.spyOn(process, 'memoryUsage');
+  const addItem = vi.fn();
+
+  beforeEach(() => {
+    vi.useFakeTimers();
+    vi.clearAllMocks();
+  });
+
+  afterEach(() => {
+    vi.useRealTimers();
+  });
+
+  it('should not warn when memory usage is below threshold', () => {
+    memoryUsageSpy.mockReturnValue({
+      rss: MEMORY_WARNING_THRESHOLD / 2,
+    } as NodeJS.MemoryUsage);
+    renderHook(() => useMemoryMonitor({ addItem }));
+    vi.advanceTimersByTime(10000);
+    expect(addItem).not.toHaveBeenCalled();
+  });
+
+  it('should warn when memory usage is above threshold', () => {
+    memoryUsageSpy.mockReturnValue({
+      rss: MEMORY_WARNING_THRESHOLD * 1.5,
+    } as NodeJS.MemoryUsage);
+    renderHook(() => useMemoryMonitor({ addItem }));
+    vi.advanceTimersByTime(MEMORY_CHECK_INTERVAL);
+    expect(addItem).toHaveBeenCalledTimes(1);
+    expect(addItem).toHaveBeenCalledWith(
+      {
+        type: MessageType.WARNING,
+        text: 'High memory usage detected: 10.50 GB. If you experience a crash, please file a bug report by running `/bug`',
+      },
+      expect.any(Number),
+    );
+  });
+
+  it('should only warn once', () => {
+    memoryUsageSpy.mockReturnValue({
+      rss: MEMORY_WARNING_THRESHOLD * 1.5,
+    } as NodeJS.MemoryUsage);
+    const { rerender } = renderHook(() => useMemoryMonitor({ addItem }));
+    vi.advanceTimersByTime(MEMORY_CHECK_INTERVAL);
+    expect(addItem).toHaveBeenCalledTimes(1);
+
+    // Rerender and advance timers, should not warn again
+    memoryUsageSpy.mockReturnValue({
+      rss: MEMORY_WARNING_THRESHOLD * 1.5,
+    } as NodeJS.MemoryUsage);
+    rerender();
+    vi.advanceTimersByTime(MEMORY_CHECK_INTERVAL);
+    expect(addItem).toHaveBeenCalledTimes(1);
+  });
+});

packages/cli/src/ui/hooks/useMemoryMonitor.ts

@@ -0,0 +1,41 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { useEffect } from 'react';
+import process from 'node:process';
+import { type HistoryItemWithoutId, MessageType } from '../types.js';
+
+export const MEMORY_WARNING_THRESHOLD = 7 * 1024 * 1024 * 1024; // 7GB in bytes
+export const MEMORY_CHECK_INTERVAL = 60 * 1000; // one minute
+
+interface MemoryMonitorOptions {
+  addItem: (item: HistoryItemWithoutId, timestamp: number) => void;
+}
+
+export const useMemoryMonitor = ({ addItem }: MemoryMonitorOptions) => {
+  useEffect(() => {
+    const intervalId = setInterval(() => {
+      const usage = process.memoryUsage().rss;
+      if (usage > MEMORY_WARNING_THRESHOLD) {
+        addItem(
+          {
+            type: MessageType.WARNING,
+            text:
+              `High memory usage detected: ${(
+                usage /
+                (1024 * 1024 * 1024)
+              ).toFixed(2)} GB. ` +
+              'If you experience a crash, please file a bug report by running `/bug`',
+          },
+          Date.now(),
+        );
+        clearInterval(intervalId);
+      }
+    }, MEMORY_CHECK_INTERVAL);
+
+    return () => clearInterval(intervalId);
+  }, [addItem]);
+};