chore: Add tests for useCurrentTime

Author: rjmunro

packages/webui/src/client/lib/__tests__/lib.test.ts

@@ -0,0 +1,50 @@
+import { useCurrentTime } from '../lib' // Adjust the import path as needed
+import { act, renderHook } from '@testing-library/react'
+
+describe('useCurrentTime Hook', () => {
+	it('should return the current time in milliseconds initially', () => {
+		const initialTime = Date.now()
+		const { result } = renderHook(() => useCurrentTime())
+		expect(result.current).toBeGreaterThanOrEqual(initialTime)
+		expect(result.current).toBeLessThanOrEqual(initialTime + 50) // Allow for a small margin
+	})
+
+	it('should update the time after the default refresh period (1000ms)', () => {
+		jest.useFakeTimers() // Enable Jest's fake timers
+		const { result } = renderHook(() => useCurrentTime())
+		const initialTime = result.current
+
+		act(() => {
+			jest.advanceTimersByTime(1000) // Advance the timers by the default refresh period
+		})
+
+		const nextSecond = Math.ceil((initialTime + 1) / 1000) * 1000 // Round to the next second
+		expect(result.current).toBeGreaterThanOrEqual(nextSecond)
+		expect(result.current).toBeLessThanOrEqual(nextSecond + 50) // Allow for a small margin
+	})
+
+	it('should update the time after a custom refresh period', () => {
+		jest.useFakeTimers() // Enable Jest's fake timers
+		const refreshPeriod = 500
+		const { result } = renderHook(() => useCurrentTime(refreshPeriod))
+		const initialTime = result.current
+
+		act(() => {
+			jest.advanceTimersByTime(refreshPeriod)
+		})
+
+		const nextInterval = Math.ceil((initialTime + 1) / refreshPeriod) * refreshPeriod // Round to the next refreshPeriod
+		expect(result.current).toBeGreaterThanOrEqual(nextInterval - 50)
+		expect(result.current).toBeLessThanOrEqual(nextInterval + 50) // Allow for a small margin
+	})
+
+	it('should clear the timeout on unmount', () => {
+		const { unmount } = renderHook(() => useCurrentTime())
+		const mockClearTimeout = jest.spyOn(global, 'clearTimeout')
+
+		unmount()
+
+		expect(mockClearTimeout).toHaveBeenCalledTimes(1)
+		// You could also assert that the timeout ID stored in the ref was passed to clearTimeout
+	})
+})