feat(tests): add comprehensive tests for ProxyHosts and Uptime components

- Introduced isolated coverage tests for ProxyHosts with various scenarios including rendering, bulk apply, and link behavior.
- Enhanced existing ProxyHosts coverage tests to include additional assertions and error handling.
- Added tests for Uptime component to verify rendering and monitoring toggling functionality.
- Created utility functions for setting labels and help texts related to proxy host settings.
- Implemented bulk settings application logic with progress tracking and error handling.
- Added toast utility tests to ensure callback functionality and ID incrementing.
- Improved type safety in test files by using appropriate TypeScript types.

frontend/src/utils/__tests__/compareHosts.test.ts

@@ -46,7 +46,8 @@ const hostB: ProxyHost = {
 
 describe('compareHosts', () => {
   it('returns 0 for unknown sort column (default case)', () => {
-    const res = compareHosts(hostA, hostB, 'unknown' as any, 'asc')
+    const compareAny = compareHosts as unknown as (a: ProxyHost, b: ProxyHost, sortColumn: string, sortDirection: 'asc' | 'desc') => number
+    const res = compareAny(hostA, hostB, 'unknown', 'asc')
     expect(res).toBe(0)
   })
 

frontend/src/utils/__tests__/toast.test.ts

@@ -0,0 +1,40 @@
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
+import { toast, toastCallbacks } from '../toast'
+
+describe('toast util', () => {
+  beforeEach(() => {
+    // Ensure callbacks set is empty before each test
+    toastCallbacks.clear()
+  })
+
+  afterEach(() => {
+    toastCallbacks.clear()
+  })
+
+  it('calls registered callbacks for each toast type', () => {
+    const mock = vi.fn()
+    toastCallbacks.add(mock)
+
+    toast.success('ok')
+    toast.error('bad')
+    toast.info('info')
+    toast.warning('warn')
+
+    expect(mock).toHaveBeenCalledTimes(4)
+    expect(mock.mock.calls[0][0]).toMatchObject({ message: 'ok', type: 'success' })
+    expect(mock.mock.calls[1][0]).toMatchObject({ message: 'bad', type: 'error' })
+    expect(mock.mock.calls[2][0]).toMatchObject({ message: 'info', type: 'info' })
+    expect(mock.mock.calls[3][0]).toMatchObject({ message: 'warn', type: 'warning' })
+  })
+
+  it('provides incrementing ids', () => {
+    const mock = vi.fn()
+    toastCallbacks.add(mock)
+    // send multiple messages
+    toast.success('one')
+    toast.success('two')
+    const firstId = mock.mock.calls[0][0].id
+    const secondId = mock.mock.calls[1][0].id
+    expect(secondId).toBeGreaterThan(firstId)
+  })
+})