feat(ST-d9sl8egw): lib/insights/token-history.ts — sprint-historiek, dag-data & PBI-aggregaat (#115)

Drie functies via prisma.$queryRaw: getSprintTokenHistory (per-sprint
aggregaat), getDayTokenData (dag-totalen met guard op lege sprintId),
getPbiTokenAggregates (per-PBI met guard). Tests voor alle drie.

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

__tests__/lib/insights/token-history.test.ts

@@ -0,0 +1,74 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest'
+
+const { mockQueryRaw } = vi.hoisted(() => ({ mockQueryRaw: vi.fn() }))
+
+vi.mock('@/lib/prisma', () => ({
+  prisma: { $queryRaw: mockQueryRaw },
+}))
+
+import {
+  getSprintTokenHistory,
+  getDayTokenData,
+  getPbiTokenAggregates,
+} from '@/lib/insights/token-history'
+
+beforeEach(() => {
+  vi.clearAllMocks()
+})
+
+describe('getSprintTokenHistory', () => {
+  it('returns mapped sprint rows', async () => {
+    mockQueryRaw.mockResolvedValueOnce([
+      { sprint_id: 'sp-1', sprint_goal: 'Goal A', total_tokens: BigInt(5000), total_cost: 0.1, job_count: BigInt(2) },
+    ])
+    const rows = await getSprintTokenHistory('user-1')
+    expect(rows).toHaveLength(1)
+    expect(rows[0].sprintId).toBe('sp-1')
+    expect(rows[0].totalTokens).toBe(5000)
+    expect(rows[0].totalCostUsd).toBe(0.1)
+    expect(rows[0].jobCount).toBe(2)
+  })
+
+  it('returns zero cost when total_cost is null', async () => {
+    mockQueryRaw.mockResolvedValueOnce([
+      { sprint_id: 'sp-2', sprint_goal: 'Goal B', total_tokens: BigInt(0), total_cost: null, job_count: BigInt(0) },
+    ])
+    const rows = await getSprintTokenHistory('user-1')
+    expect(rows[0].totalCostUsd).toBe(0)
+  })
+})
+
+describe('getDayTokenData', () => {
+  it('returns empty array for empty sprintId', async () => {
+    const rows = await getDayTokenData('user-1', '')
+    expect(rows).toHaveLength(0)
+    expect(mockQueryRaw).not.toHaveBeenCalled()
+  })
+
+  it('maps day rows with ISO date string', async () => {
+    mockQueryRaw.mockResolvedValueOnce([
+      { day: new Date('2026-05-01T00:00:00Z'), total_tokens: BigInt(2000), total_cost: 0.05 },
+    ])
+    const rows = await getDayTokenData('user-1', 'sprint-1')
+    expect(rows).toHaveLength(1)
+    expect(rows[0].day).toBe('2026-05-01')
+    expect(rows[0].totalTokens).toBe(2000)
+  })
+})
+
+describe('getPbiTokenAggregates', () => {
+  it('returns empty array for empty sprintId', async () => {
+    const rows = await getPbiTokenAggregates('user-1', '')
+    expect(rows).toHaveLength(0)
+    expect(mockQueryRaw).not.toHaveBeenCalled()
+  })
+
+  it('maps pbi rows', async () => {
+    mockQueryRaw.mockResolvedValueOnce([
+      { pbi_id: 'pbi-1', pbi_code: 'M1', pbi_title: 'First PBI', total_tokens: BigInt(3000), total_cost: 0.08 },
+    ])
+    const rows = await getPbiTokenAggregates('user-1', 'sprint-1')
+    expect(rows[0].pbiCode).toBe('M1')
+    expect(rows[0].totalTokens).toBe(3000)
+  })
+})