feat: add unit tests and CI configuration

lib/hooks/__tests__/useOnlineStatus.test.ts

@@ -0,0 +1,34 @@
+import { describe, it, expect } from 'vitest'
+import { renderHook, act } from '@testing-library/react'
+import { useOnlineStatus } from '../useOnlineStatus'
+
+describe('useOnlineStatus', () => {
+  it('returns true initially', () => {
+    const { result } = renderHook(() => useOnlineStatus())
+    expect(result.current).toBe(true)
+  })
+
+  it('returns false when offline event fires', () => {
+    const { result } = renderHook(() => useOnlineStatus())
+
+    act(() => {
+      window.dispatchEvent(new Event('offline'))
+    })
+
+    expect(result.current).toBe(false)
+  })
+
+  it('returns true when online event fires after offline', () => {
+    const { result } = renderHook(() => useOnlineStatus())
+
+    act(() => {
+      window.dispatchEvent(new Event('offline'))
+    })
+    expect(result.current).toBe(false)
+
+    act(() => {
+      window.dispatchEvent(new Event('online'))
+    })
+    expect(result.current).toBe(true)
+  })
+})

lib/hooks/__tests__/useVisibilityPolling.test.ts

@@ -0,0 +1,99 @@
+import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest'
+import { renderHook, act } from '@testing-library/react'
+import { useVisibilityPolling } from '../useVisibilityPolling'
+
+describe('useVisibilityPolling', () => {
+  beforeEach(() => {
+    vi.useFakeTimers()
+  })
+
+  afterEach(() => {
+    vi.useRealTimers()
+  })
+
+  it('starts polling and calls callback at the visible interval', () => {
+    const callback = vi.fn()
+
+    renderHook(() =>
+      useVisibilityPolling(callback, {
+        visibleInterval: 1000,
+        hiddenInterval: null,
+      })
+    )
+
+    // Initial call might not happen immediately; advance to trigger interval
+    act(() => {
+      vi.advanceTimersByTime(1000)
+    })
+
+    expect(callback).toHaveBeenCalled()
+  })
+
+  it('reports isPolling as true when active', () => {
+    const callback = vi.fn()
+
+    const { result } = renderHook(() =>
+      useVisibilityPolling(callback, {
+        visibleInterval: 1000,
+        hiddenInterval: null,
+      })
+    )
+
+    expect(result.current.isPolling).toBe(true)
+  })
+
+  it('calls callback multiple times over multiple intervals', () => {
+    const callback = vi.fn()
+
+    renderHook(() =>
+      useVisibilityPolling(callback, {
+        visibleInterval: 500,
+        hiddenInterval: null,
+      })
+    )
+
+    act(() => {
+      vi.advanceTimersByTime(1500)
+    })
+
+    expect(callback.mock.calls.length).toBeGreaterThanOrEqual(2)
+  })
+
+  it('triggerPoll calls callback immediately', () => {
+    const callback = vi.fn()
+
+    const { result } = renderHook(() =>
+      useVisibilityPolling(callback, {
+        visibleInterval: 10000,
+        hiddenInterval: null,
+      })
+    )
+
+    act(() => {
+      result.current.triggerPoll()
+    })
+
+    expect(callback).toHaveBeenCalled()
+    expect(result.current.lastPollTime).not.toBeNull()
+  })
+
+  it('cleans up intervals on unmount', () => {
+    const callback = vi.fn()
+
+    const { unmount } = renderHook(() =>
+      useVisibilityPolling(callback, {
+        visibleInterval: 1000,
+        hiddenInterval: null,
+      })
+    )
+
+    unmount()
+    callback.mockClear()
+
+    act(() => {
+      vi.advanceTimersByTime(5000)
+    })
+
+    expect(callback).not.toHaveBeenCalled()
+  })
+})