feat(create_story): optionele sprint_id om story aan sprint te koppelen

create_story accepteert nu een optionele sprint_id; bij meegeven wordt de
story aangemaakt met status=IN_SPRINT (sprint moet bij hetzelfde product
horen als de PBI). Handler geextraheerd naar handleCreateStory voor
testbaarheid; nieuwe unit-tests in __tests__/create-story.test.ts.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

__tests__/create-story.test.ts

@@ -0,0 +1,141 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest'
+
+vi.mock('../src/prisma.js', () => ({
+  prisma: {
+    pbi: { findUnique: vi.fn() },
+    sprint: { findUnique: vi.fn() },
+    story: {
+      findFirst: vi.fn(),
+      findMany: vi.fn(),
+      create: vi.fn(),
+    },
+  },
+}))
+
+vi.mock('../src/auth.js', () => ({
+  requireWriteAccess: vi.fn(),
+  PermissionDeniedError: class PermissionDeniedError extends Error {
+    constructor(message = 'Demo accounts cannot perform write operations') {
+      super(message)
+      this.name = 'PermissionDeniedError'
+    }
+  },
+}))
+
+vi.mock('../src/access.js', () => ({
+  userCanAccessProduct: vi.fn(),
+}))
+
+import { prisma } from '../src/prisma.js'
+import { requireWriteAccess } from '../src/auth.js'
+import { userCanAccessProduct } from '../src/access.js'
+import { handleCreateStory } from '../src/tools/create-story.js'
+
+const mockPrisma = prisma as unknown as {
+  pbi: { findUnique: ReturnType<typeof vi.fn> }
+  sprint: { findUnique: ReturnType<typeof vi.fn> }
+  story: {
+    findFirst: ReturnType<typeof vi.fn>
+    findMany: ReturnType<typeof vi.fn>
+    create: ReturnType<typeof vi.fn>
+  }
+}
+const mockRequireWriteAccess = requireWriteAccess as ReturnType<typeof vi.fn>
+const mockUserCanAccessProduct = userCanAccessProduct as ReturnType<typeof vi.fn>
+
+const PRODUCT_ID = 'prod-1'
+const PBI_ID = 'pbi-1'
+const SPRINT_ID = 'spr-1'
+const USER_ID = 'user-1'
+
+beforeEach(() => {
+  vi.clearAllMocks()
+  mockRequireWriteAccess.mockResolvedValue({ userId: USER_ID, tokenId: 'tok-1', username: 'alice', isDemo: false })
+  mockUserCanAccessProduct.mockResolvedValue(true)
+  mockPrisma.pbi.findUnique.mockResolvedValue({ product_id: PRODUCT_ID })
+  mockPrisma.story.findMany.mockResolvedValue([])
+  mockPrisma.story.findFirst.mockResolvedValue(null)
+  mockPrisma.story.create.mockImplementation((args: { data: Record<string, unknown> }) =>
+    Promise.resolve({ id: 'story-1', created_at: new Date('2026-05-14T10:00:00Z'), ...args.data }),
+  )
+})
+
+function parseResult(result: Awaited<ReturnType<typeof handleCreateStory>>) {
+  const text = result.content?.[0]?.type === 'text' ? result.content[0].text : ''
+  try { return JSON.parse(text) } catch { return text }
+}
+
+function errorText(result: Awaited<ReturnType<typeof handleCreateStory>>): string {
+  return result.content?.[0]?.type === 'text' ? result.content[0].text : ''
+}
+
+describe('handleCreateStory', () => {
+  it('without sprint_id: creates story with status OPEN and no sprint', async () => {
+    const result = await handleCreateStory({ pbi_id: PBI_ID, title: 'A story', priority: 2 })
+
+    expect(mockPrisma.sprint.findUnique).not.toHaveBeenCalled()
+    const data = mockPrisma.story.create.mock.calls[0][0].data
+    expect(data.status).toBe('OPEN')
+    expect(data.sprint_id).toBeNull()
+    expect(data.product_id).toBe(PRODUCT_ID)
+    expect(parseResult(result).status).toBe('OPEN')
+  })
+
+  it('with valid sprint_id: links story to sprint with status IN_SPRINT', async () => {
+    mockPrisma.sprint.findUnique.mockResolvedValue({ product_id: PRODUCT_ID })
+
+    const result = await handleCreateStory({
+      pbi_id: PBI_ID,
+      title: 'A story',
+      priority: 2,
+      sprint_id: SPRINT_ID,
+    })
+
+    expect(mockPrisma.sprint.findUnique).toHaveBeenCalledWith({
+      where: { id: SPRINT_ID },
+      select: { product_id: true },
+    })
+    const data = mockPrisma.story.create.mock.calls[0][0].data
+    expect(data.status).toBe('IN_SPRINT')
+    expect(data.sprint_id).toBe(SPRINT_ID)
+    expect(parseResult(result).sprint_id).toBe(SPRINT_ID)
+  })
+
+  it('rejects a non-existent sprint_id', async () => {
+    mockPrisma.sprint.findUnique.mockResolvedValue(null)
+
+    const result = await handleCreateStory({
+      pbi_id: PBI_ID,
+      title: 'A story',
+      priority: 2,
+      sprint_id: 'missing',
+    })
+
+    expect(mockPrisma.story.create).not.toHaveBeenCalled()
+    expect(errorText(result)).toMatch(/Sprint missing not found/)
+  })
+
+  it('rejects a sprint from a different product', async () => {
+    mockPrisma.sprint.findUnique.mockResolvedValue({ product_id: 'other-product' })
+
+    const result = await handleCreateStory({
+      pbi_id: PBI_ID,
+      title: 'A story',
+      priority: 2,
+      sprint_id: SPRINT_ID,
+    })
+
+    expect(mockPrisma.story.create).not.toHaveBeenCalled()
+    expect(errorText(result)).toMatch(/different product/)
+  })
+
+  it('returns error when PBI not found', async () => {
+    mockPrisma.pbi.findUnique.mockResolvedValue(null)
+
+    const result = await handleCreateStory({ pbi_id: 'missing', title: 'A story', priority: 2 })
+
+    expect(mockPrisma.sprint.findUnique).not.toHaveBeenCalled()
+    expect(mockPrisma.story.create).not.toHaveBeenCalled()
+    expect(errorText(result)).toMatch(/PBI missing not found/)
+  })
+})