feat: getVerifyResultStats helper + 5 Vitest-tests (lib/insights/verify-stats.ts) (#38)

Aggregeert verify_result counts (ALIGNED/PARTIAL/EMPTY/DIVERGENT) en top-5 EMPTY/DIVERGENT
jobs over de laatste N dagen voor de ingelogde gebruiker.

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

__tests__/lib/insights/verify-stats.test.ts

@@ -0,0 +1,112 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest'
+
+const { mockGroupBy, mockFindMany } = vi.hoisted(() => ({
+  mockGroupBy: vi.fn(),
+  mockFindMany: vi.fn(),
+}))
+
+vi.mock('@/lib/prisma', () => ({
+  prisma: {
+    claudeJob: {
+      groupBy: mockGroupBy,
+      findMany: mockFindMany,
+    },
+  },
+}))
+
+import { getVerifyResultStats } from '@/lib/insights/verify-stats'
+
+const USER_ID = 'user-1'
+
+const makeJob = (id: string, verifyResult: string, daysAgo: number) => {
+  const finishedAt = new Date()
+  finishedAt.setDate(finishedAt.getDate() - daysAgo)
+  return {
+    id,
+    finished_at: finishedAt,
+    task: { id: `task-${id}`, title: `Task ${id}` },
+    product: { id: 'prod-1', name: 'Scrum4Me' },
+    verify_result: verifyResult,
+  }
+}
+
+beforeEach(() => {
+  vi.clearAllMocks()
+})
+
+describe('getVerifyResultStats', () => {
+  it('returns counts in ALIGNED→PARTIAL→EMPTY→DIVERGENT order', async () => {
+    mockGroupBy.mockResolvedValue([
+      { verify_result: 'DIVERGENT', _count: { _all: 2 } },
+      { verify_result: 'ALIGNED', _count: { _all: 10 } },
+      { verify_result: 'EMPTY', _count: { _all: 3 } },
+      { verify_result: 'PARTIAL', _count: { _all: 1 } },
+    ])
+    mockFindMany.mockResolvedValue([])
+
+    const stats = await getVerifyResultStats(USER_ID)
+
+    expect(stats.counts.map(c => c.result)).toEqual([
+      'ALIGNED', 'PARTIAL', 'EMPTY', 'DIVERGENT',
+    ])
+    expect(stats.counts.map(c => c.count)).toEqual([10, 1, 3, 2])
+  })
+
+  it('omits results with zero count from groupBy', async () => {
+    mockGroupBy.mockResolvedValue([
+      { verify_result: 'ALIGNED', _count: { _all: 5 } },
+    ])
+    mockFindMany.mockResolvedValue([])
+
+    const stats = await getVerifyResultStats(USER_ID)
+
+    expect(stats.counts).toHaveLength(1)
+    expect(stats.counts[0]).toEqual({ result: 'ALIGNED', count: 5 })
+  })
+
+  it('maps topEmpty jobs correctly', async () => {
+    mockGroupBy.mockResolvedValue([])
+    const job = makeJob('j1', 'EMPTY', 2)
+    // First findMany call → topEmpty, second → topDivergent
+    mockFindMany
+      .mockResolvedValueOnce([job])
+      .mockResolvedValueOnce([])
+
+    const stats = await getVerifyResultStats(USER_ID)
+
+    expect(stats.topEmpty).toHaveLength(1)
+    expect(stats.topEmpty[0]).toMatchObject({
+      jobId: 'j1',
+      taskId: 'task-j1',
+      taskTitle: 'Task j1',
+      productId: 'prod-1',
+      productName: 'Scrum4Me',
+    })
+  })
+
+  it('topDivergent is ordered most-recent first (from DB order)', async () => {
+    mockGroupBy.mockResolvedValue([])
+    const jobs = [
+      makeJob('jOld', 'DIVERGENT', 10),
+      makeJob('jNew', 'DIVERGENT', 1),
+    ]
+    mockFindMany
+      .mockResolvedValueOnce([])       // topEmpty
+      .mockResolvedValueOnce(jobs)     // topDivergent (already sorted by Prisma orderBy)
+
+    const stats = await getVerifyResultStats(USER_ID)
+
+    expect(stats.topDivergent.map(j => j.jobId)).toEqual(['jOld', 'jNew'])
+  })
+
+  it('returns empty stats when no jobs found', async () => {
+    mockGroupBy.mockResolvedValue([])
+    mockFindMany.mockResolvedValue([])
+
+    const stats = await getVerifyResultStats(USER_ID)
+
+    expect(stats.counts).toEqual([])
+    expect(stats.topEmpty).toEqual([])
+    expect(stats.topDivergent).toEqual([])
+  })
+})