feat(dimensions): show the value's name after picking, and let an unused custom dimension be deleted (#2219) (#2255)

* feat(dimensions): show the value's name after picking, and let an unused custom dimension be deleted (#2219)

Two things from the same Discord report, both in bookkeeping from the
transaction view:

1. After picking a kostnadsställe the field showed only the code ("1").
   DimensionCombobox now writes the value's full name under the field once
   a code is committed, exactly as AccountCombobox does for the account
   name (looked up in the full registry so an archived code stays
   readable). The input text itself stays the code: the blur/revert logic
   keys on it.

2. A self-created dimension could not be removed at all: the DB already
   allowed it (enforce_dimension_registry_guards lets a non-system
   dimension go when no posted/reversed line carries its number, and the
   value retention trigger fires on the cascade), but no route or UI
   asked. New DELETE /api/dimensions/[id]: 400 DIMENSION_SYSTEM_DELETE for
   kostnadsställe/projekt, the guard's own Swedish P0001 verbatim as 409
   DIMENSION_REFERENCED, 404, and a happy path; the register gets a quiet
   "Ta bort dimension" link for the active custom dimension behind a
   DestructiveConfirmDialog. Keys added to sv and en.

Closes #2219

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VnConrmMCxJRQ5kfiPPWyy

* test: satisfy the TypeScript ratchet for two test files main inherited from #2247 and #2242

accounts-route.test.ts built SyncResult literals without the
requestedFromDate / historyNarrowed fields #2247 added (vitest does not
typecheck, so it passed locally); fiscal-periods route.test.ts got two
more one-argument POST(req) calls from #2242 in a file already at its
ratchet baseline. Both files now typecheck; the ratchet runs clean.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VnConrmMCxJRQ5kfiPPWyy

---------

Co-authored-by: Jakob Wennberg <311770904+jakobwennberg-oss@users.noreply.github.com>
Co-authored-by: Claude Fable 5.1 <noreply@anthropic.com>

app/api/bookkeeping/fiscal-periods/__tests__/route.test.ts

@@ -384,7 +384,7 @@ describe('POST /api/bookkeeping/fiscal-periods', () => {
       overlapping: [],
     })
     const req = createMockRequest({ name: '2022/2023', period_start: '2022-07-22', period_end: '2023-12-31' })
-    const res = await POST(req)
+    const res = await POST(req, { params: Promise.resolve({}) })
     expect(res.status).toBe(200)
   })
 
@@ -393,7 +393,7 @@ describe('POST /api/bookkeeping/fiscal-periods', () => {
       allPeriods: [{ id: 'p2024', period_start: '2024-01-01', period_end: '2024-12-31', is_closed: false }],
     })
     const req = createMockRequest({ name: 'FY 2025', period_start: '2025-01-15', period_end: '2025-12-31' })
-    const res = await POST(req)
+    const res = await POST(req, { params: Promise.resolve({}) })
     expect(res.status).toBe(400)
     const body = await res.json()
     expect(body.error).toMatch(/1st of a month/)

app/api/dimensions/[id]/route.ts

@@ -1,5 +1,6 @@
 /**
  * PATCH /api/dimensions/[id]: update a dimension (name / is_active / sort_order).
+ * DELETE /api/dimensions/[id]: remove a custom dimension nobody has booked on.
  *
  * Guard rails:
  *   - Renaming an is_system dimension (1 = Kostnadsställe, 6 = Projekt) is
@@ -7,6 +8,13 @@
  *     döpas om"). Archiving (is_active=false) and reordering remain allowed.
  *   - sie_dim_no / is_system are immutable at the DB level
  *     (enforce_dimension_registry_guards) and not accepted here at all.
+ *   - DELETE (issue #2219): a system dimension answers 400
+ *     DIMENSION_SYSTEM_DELETE before the DB is asked. A custom dimension whose
+ *     number is tagged on any posted/reversed line is refused by the same DB
+ *     guard with a P0001 that names the dimension; that message rides the 409
+ *     DIMENSION_REFERENCED envelope verbatim. Values cascade (ON DELETE
+ *     CASCADE) and the value retention trigger fires on the cascade too, so
+ *     nothing booked can ever be pulled out from under a verifikat.
  */
 import { NextResponse } from 'next/server'
 import { ensureInitialized } from '@/lib/init'
@@ -77,3 +85,61 @@ export const PATCH = withRouteContext(
   },
   { requireWrite: true },
 )
+
+export const DELETE = withRouteContext(
+  'dimension.delete',
+  async (_request, ctx, { params }: { params: Promise<{ id: string }> }) => {
+    const { id } = await params
+    const { supabase, companyId, log, requestId } = ctx
+    const opLog = log.child({ dimensionId: id })
+
+    const { data: existing, error: fetchError } = await supabase
+      .from('dimensions')
+      .select('id, name, is_system')
+      .eq('id', id)
+      .eq('company_id', companyId)
+      .maybeSingle()
+
+    if (fetchError) {
+      opLog.error('dimension fetch failed', fetchError)
+      return errorResponse(fetchError, opLog, { requestId })
+    }
+    if (!existing) {
+      return errorResponseFromCode('DIMENSION_NOT_FOUND', opLog, { requestId })
+    }
+    if (existing.is_system) {
+      return errorResponseFromCode('DIMENSION_SYSTEM_DELETE', opLog, { requestId })
+    }
+
+    const { data, error } = await supabase
+      .from('dimensions')
+      .delete()
+      .eq('id', id)
+      .eq('company_id', companyId)
+      .select('id')
+
+    if (error) {
+      // P0001 = plpgsql RAISE EXCEPTION: the registry guard (or the value
+      // retention trigger on the cascade) refusing the delete. Surface its
+      // Swedish message verbatim: it names the dimension / code.
+      if (error.code === 'P0001') {
+        return errorResponseFromCode('DIMENSION_REFERENCED', opLog, {
+          requestId,
+          messageSv: error.message,
+        })
+      }
+      opLog.error('dimension delete failed', error)
+      return errorResponseFromCode('DIMENSION_DELETE_FAILED', opLog, {
+        requestId,
+        details: { reason: getUserErrorMessage(error) },
+      })
+    }
+
+    if (!data || data.length === 0) {
+      return errorResponseFromCode('DIMENSION_NOT_FOUND', opLog, { requestId })
+    }
+
+    return NextResponse.json({ success: true })
+  },
+  { requireWrite: true },
+)

app/api/dimensions/__tests__/id.test.ts

@@ -1,5 +1,6 @@
 /**
- * Tests for PATCH /api/dimensions/[id] (update dimension).
+ * Tests for PATCH /api/dimensions/[id] (update dimension) and
+ * DELETE /api/dimensions/[id] (remove an unused custom dimension, #2219).
  *
  * Covers: 401, empty-body validation (400), 404, the is_system name-lock
  * ("Systemdimensioner kan inte döpas om", 400 DIMENSION_SYSTEM_RENAME),
@@ -34,7 +35,7 @@ vi.mock('@/lib/auth/require-write', () => ({
 
 vi.mock('@/lib/init', () => ({ ensureInitialized: vi.fn() }))
 
-import { PATCH } from '../[id]/route'
+import { PATCH, DELETE } from '../[id]/route'
 
 const params = () => createMockRouteParams({ id: 'dim-1' })
 
@@ -137,3 +138,60 @@ describe('PATCH /api/dimensions/[id]', () => {
     expect(body.data.sort_order).toBe(30)
   })
 })
+
+describe('DELETE /api/dimensions/[id]', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+    reset()
+    requireAuthMock.mockResolvedValue({ user: { id: 'user-1' }, supabase })
+    requireWriteMock.mockResolvedValue({ ok: true })
+  })
+
+  const del = () => DELETE(createMockRequest('/api/dimensions/dim-1', { method: 'DELETE' }), params())
+
+  it('returns 401 when not authenticated', async () => {
+    requireAuthMock.mockResolvedValue({
+      error: NextResponse.json({ error: 'Unauthorized' }, { status: 401 }),
+    })
+    const response = await del()
+    expect(response.status).toBe(401)
+  })
+
+  it('returns 404 when the dimension does not belong to the company', async () => {
+    enqueue({ data: null })
+    const { status, body } = await parseJsonResponse<{ error: { code: string } }>(await del())
+    expect(status).toBe(404)
+    expect(body.error.code).toBe('DIMENSION_NOT_FOUND')
+  })
+
+  it('refuses a system dimension with 400 DIMENSION_SYSTEM_DELETE before touching the DB', async () => {
+    enqueue({ data: { id: 'dim-1', name: 'Kostnadsställe', is_system: true } })
+    const { status, body } = await parseJsonResponse<{ error: { code: string; message: string } }>(await del())
+    expect(status).toBe(400)
+    expect(body.error.code).toBe('DIMENSION_SYSTEM_DELETE')
+    expect(body.error.message).toContain('avaktivera')
+  })
+
+  it('surfaces the DB guard verbatim as 409 DIMENSION_REFERENCED when posted lines carry the number', async () => {
+    enqueue({ data: { id: 'dim-1', name: 'Avdelning', is_system: false } })
+    enqueue({
+      data: null,
+      error: {
+        code: 'P0001',
+        message: 'Dimensionen 7 (Avdelning) används på bokförda verifikat och kan inte tas bort — avaktivera den istället.',
+      },
+    })
+    const { status, body } = await parseJsonResponse<{ error: { code: string; message: string } }>(await del())
+    expect(status).toBe(409)
+    expect(body.error.code).toBe('DIMENSION_REFERENCED')
+    expect(body.error.message).toContain('Avdelning')
+  })
+
+  it('deletes an unused custom dimension (happy path)', async () => {
+    enqueue({ data: { id: 'dim-1', name: 'Avdelning', is_system: false } })
+    enqueue({ data: [{ id: 'dim-1' }] })
+    const { status, body } = await parseJsonResponse<{ success: boolean }>(await del())
+    expect(status).toBe(200)
+    expect(body.success).toBe(true)
+  })
+})