feat: email notifications via Resend on new incident

tests/lib/notifications/email.test.ts

@@ -0,0 +1,66 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest'
+
+const { mockSend, mockFrom } = vi.hoisted(() => ({
+  mockSend: vi.fn(),
+  mockFrom: vi.fn(),
+}))
+
+vi.mock('resend', () => {
+  function MockResend() {}
+  MockResend.prototype.emails = { send: mockSend }
+  return { Resend: MockResend }
+})
+
+vi.mock('@/lib/supabase/server', () => ({
+  createClient: vi.fn().mockResolvedValue({ from: mockFrom }),
+}))
+
+import { sendNewIncidentEmail } from '@/lib/notifications/email'
+
+const mockIncidentRow = {
+  reported_at: '2026-07-10T09:00:00Z',
+  sites: { name: 'SCW1' },
+  reporter: { name: 'John Doe' },
+}
+
+function setupMocks(recipientData: object[]) {
+  mockFrom.mockImplementation((table: string) => {
+    if (table === 'users') {
+      return {
+        select: vi.fn().mockReturnThis(),
+        in: vi.fn().mockReturnThis(),
+        eq: vi.fn().mockResolvedValue({ data: recipientData, error: null }),
+      }
+    }
+    return {
+      select: vi.fn().mockReturnThis(),
+      eq: vi.fn().mockReturnThis(),
+      single: vi.fn().mockResolvedValue({ data: mockIncidentRow, error: null }),
+    }
+  })
+}
+
+beforeEach(() => {
+  vi.clearAllMocks()
+  mockSend.mockResolvedValue({ data: { id: 'email-123' }, error: null })
+  setupMocks([
+    { email: 'supervisor@setiacorp.com', name: 'Ahmad', role: 'supervisor' },
+    { email: 'hse@setiacorp.com', name: 'Priya', role: 'hse' },
+  ])
+})
+
+describe('sendNewIncidentEmail', () => {
+  it('sends email to supervisor and hse users', async () => {
+    await sendNewIncidentEmail('inc-001', 'site-001', 'SCW1-202607-0001', 'near_miss')
+    expect(mockSend).toHaveBeenCalledTimes(1)
+    const call = mockSend.mock.calls[0][0]
+    expect(call.to).toEqual(expect.arrayContaining(['supervisor@setiacorp.com', 'hse@setiacorp.com']))
+    expect(call.subject).toContain('SCW1-202607-0001')
+  })
+
+  it('does not send if no recipients', async () => {
+    setupMocks([])
+    await sendNewIncidentEmail('inc-001', 'site-001', 'SCW1-202607-0001', 'near_miss')
+    expect(mockSend).not.toHaveBeenCalled()
+  })
+})