fix(vat): complete account treatment enforcement (#1593)

* fix(vat): complete account treatment enforcement

* docs(api): refresh account endpoint skill

* fix(mcp): preserve ruta 05 compatibility

* test(vat): seed migration constraint fixtures

* docs(vat): clarify treatment precedence

---------

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

lib/import/__tests__/account-sync.test.ts

@@ -121,6 +121,22 @@ describe('syncMappedAccounts: create pass', () => {
     })
   })
 
+  it('derives the booking rate for a confirmed treatment when the rate is unset', async () => {
+    const { supabase, inserts } = buildCapturingSupabase()
+    const result = await run(supabase, [
+      mapping({
+        sourceAccount: '4056',
+        targetAccount: '4056',
+        sourceName: 'Inköp varor EU',
+        defaultVatTreatment: 'reverse_charge_eu_goods',
+        defaultVatRate: null,
+        vatTreatmentReviewed: true,
+      }),
+    ])
+    expect(result.error).toBeNull()
+    expect(inserts[0].default_vat_rate).toBe(0.25)
+  })
+
   it('creates a missing BAS account with the BAS default name when the file has no custom name', async () => {
     const { supabase, inserts } = buildCapturingSupabase()
 

lib/import/__tests__/account-vat-treatment.test.ts

@@ -1,6 +1,7 @@
 import { describe, expect, it } from 'vitest'
 import {
   applyVatTreatmentReview,
+  enrichChangedAccountMappingWithVat,
   enrichAccountMappingsWithVat,
 } from '../account-vat-treatment'
 import type { AccountMapping } from '../types'
@@ -32,28 +33,6 @@ describe('enrichAccountMappingsWithVat', () => {
     })
   })
 
-  it('requires review for suggested class 5 and 6 purchase treatments', () => {
-    const results = enrichAccountMappingsWithVat(
-      [
-        mapping('5010', 'Inköp tjänst EU'),
-        mapping('6010', 'Inköp tjänst utanför EU'),
-      ],
-      [],
-    )
-    expect(results).toEqual([
-      expect.objectContaining({
-        defaultVatTreatment: 'reverse_charge_eu_services',
-        requiresVatTreatmentReview: true,
-        vatTreatmentReviewed: false,
-      }),
-      expect.objectContaining({
-        defaultVatTreatment: 'export_services',
-        requiresVatTreatmentReview: true,
-        vatTreatmentReviewed: false,
-      }),
-    ])
-  })
-
   it('keeps an existing account treatment without asking again', () => {
     const [result] = enrichAccountMappingsWithVat(
       [mapping('3041', 'Försäljning tjänst 25% sv')],
@@ -70,25 +49,99 @@ describe('enrichAccountMappingsWithVat', () => {
       requiresVatTreatmentReview: false,
     })
   })
+
+  it('preserves an existing booking rate when suggesting a missing treatment', () => {
+    const [result] = enrichAccountMappingsWithVat(
+      [mapping('3041', 'Försäljning tjänst 25% sv')],
+      [{
+        account_number: '3041',
+        default_vat_treatment: null,
+        default_vat_rate: 0.12,
+      } as never],
+    )
+    expect(result.defaultVatTreatment).toBe('standard_25')
+    expect(result.defaultVatRate).toBe(0.12)
+  })
+
+  it('requires review for a suggested class 6 service treatment', () => {
+    const [result] = enrichAccountMappingsWithVat(
+      [mapping('6545', 'Inköp tjänster utanför EU 25%')],
+      [],
+    )
+    expect(result).toMatchObject({
+      defaultVatTreatment: 'reverse_charge_non_eu_services',
+      requiresVatTreatmentReview: true,
+      vatTreatmentReviewed: false,
+    })
+  })
 })
 
 describe('applyVatTreatmentReview', () => {
-  it('marks only the selected row reviewed, including class 5 and 6 accounts', () => {
-    const mappings = [
-      mapping('5010', 'Inköp tjänst EU'),
-      mapping('3041', 'Försäljning tjänst 25% sv'),
-    ]
-    const result = applyVatTreatmentReview(
+  it('persists a suggestion only after an explicit row confirmation', () => {
+    const mappings = enrichAccountMappingsWithVat([
+      mapping('4056', 'Inköp varor 25% EU'),
+    ], [])
+
+    expect(mappings[0].vatTreatmentReviewed).toBe(false)
+    const reviewed = applyVatTreatmentReview(
       mappings,
-      '5010',
-      'reverse_charge_eu_services',
-      0.25,
+      '4056',
+      mappings[0].defaultVatTreatment ?? null,
+      mappings[0].defaultVatRate ?? null,
     )
-    expect(result[0]).toMatchObject({
-      defaultVatTreatment: 'reverse_charge_eu_services',
-      defaultVatRate: 0.25,
+    expect(reviewed[0]).toMatchObject({
+      defaultVatTreatment: 'reverse_charge_eu_goods',
+      vatTreatmentReviewed: true,
+      vatTreatmentSuggested: false,
+    })
+  })
+
+  it('clears hidden review state on remap and restores it on identity mapping', () => {
+    const [suggested] = enrichAccountMappingsWithVat([
+      mapping('4056', 'Inköp varor 25% EU'),
+    ], [])
+
+    const [remapped] = enrichAccountMappingsWithVat([{
+      ...suggested,
+      targetAccount: '4010',
+      targetName: 'Inköp material',
+    }], [])
+    expect(remapped).toMatchObject({
+      defaultVatTreatment: null,
+      requiresVatTreatmentReview: false,
+      vatTreatmentReviewed: true,
+    })
+
+    const [identity] = enrichAccountMappingsWithVat([{
+      ...remapped,
+      targetAccount: '4056',
+      targetName: 'Inköp varor 25% EU',
+    }], [])
+    expect(identity).toMatchObject({
+      defaultVatTreatment: 'reverse_charge_eu_goods',
+      requiresVatTreatmentReview: true,
+      vatTreatmentReviewed: false,
+    })
+  })
+
+  it('preserves another row review when one mapping changes', () => {
+    const initial = enrichAccountMappingsWithVat([
+      mapping('3041', 'Försäljning tjänst 25% sv'),
+      mapping('4056', 'Inköp varor 25% EU'),
+    ], [])
+    const reviewed = applyVatTreatmentReview(initial, '3041', 'exempt', 0)
+    const remapped = enrichChangedAccountMappingWithVat(
+      reviewed.map((item) => item.sourceAccount === '4056'
+        ? { ...item, targetAccount: '4010', targetName: 'Inköp material' }
+        : item),
+      '4056',
+      [],
+    )
+
+    expect(remapped[0]).toMatchObject({
+      defaultVatTreatment: 'exempt',
+      defaultVatRate: 0,
       vatTreatmentReviewed: true,
     })
-    expect(result[1].vatTreatmentReviewed).toBeUndefined()
   })
 })

lib/import/account-sync.ts

@@ -14,7 +14,12 @@ import { classifyAccount } from '@/lib/bookkeeping/account-classifier'
 import { computeSRUCode } from '@/lib/bookkeeping/bas-data/sru-mapping'
 import { fetchAllRows } from '@/lib/supabase/fetch-all'
 import type { AccountMapping } from './types'
-import { isAccountVatTreatment, type AccountVatTreatment } from '@/lib/vat/account-vat-treatment'
+import {
+  defaultRateForVatTreatment,
+  isAccountVatTreatment,
+  isVatTreatmentAllowedForAccountClass,
+  type AccountVatTreatment,
+} from '@/lib/vat/account-vat-treatment'
 
 export interface AccountSyncResult {
   /** Accounts inserted into chart_of_accounts */
@@ -164,9 +169,19 @@ export async function syncMappedAccounts(
       result.error = `Invalid VAT treatment for account ${mapping.sourceAccount}`
       return result
     }
+    const accountClass = Number(mapping.targetAccount.charAt(0))
+    if (
+      mapping.defaultVatTreatment &&
+      !isVatTreatmentAllowedForAccountClass(mapping.defaultVatTreatment, accountClass)
+    ) {
+      result.error = `VAT treatment is not valid for account ${mapping.sourceAccount}`
+      return result
+    }
     vatDefaults.set(mapping.targetAccount, {
       treatment: mapping.defaultVatTreatment ?? null,
-      rate: mapping.defaultVatRate ?? null,
+      rate: mapping.defaultVatTreatment && mapping.defaultVatRate == null
+        ? defaultRateForVatTreatment(mapping.defaultVatTreatment, accountClass)
+        : mapping.defaultVatRate ?? null,
     })
   }
 

lib/import/account-vat-treatment.ts

@@ -19,7 +19,16 @@ export function enrichAccountMappingsWithVat(
   )
 
   return mappings.map((mapping) => {
-    if (!mapping.targetAccount || mapping.sourceAccount !== mapping.targetAccount) return mapping
+    if (!mapping.targetAccount || mapping.sourceAccount !== mapping.targetAccount) {
+      return {
+        ...mapping,
+        defaultVatTreatment: null,
+        defaultVatRate: null,
+        vatTreatmentSuggested: false,
+        vatTreatmentReviewed: true,
+        requiresVatTreatmentReview: false,
+      }
+    }
     const accountClass = Number(mapping.sourceAccount.charAt(0))
     if (accountClass < 3 || accountClass > 6) return mapping
 
@@ -39,10 +48,10 @@ export function enrichAccountMappingsWithVat(
     return {
       ...mapping,
       defaultVatTreatment: suggestion?.treatment ?? null,
-      defaultVatRate: suggestion?.rate ?? existing?.default_vat_rate ?? null,
+      defaultVatRate: existing?.default_vat_rate ?? suggestion?.rate ?? null,
       vatTreatmentSuggested: Boolean(suggestion),
       vatTreatmentReviewed: false,
-      requiresVatTreatmentReview: accountClass >= 3 && accountClass <= 6,
+      requiresVatTreatmentReview: accountClass === 3 || accountClass === 4 || Boolean(suggestion),
     }
   })
 }
@@ -65,3 +74,15 @@ export function applyVatTreatmentReview(
       : mapping
   )
 }
+
+export function enrichChangedAccountMappingWithVat(
+  mappings: AccountMapping[],
+  sourceAccount: string,
+  existingAccounts: BASAccount[],
+): AccountMapping[] {
+  return mappings.map((mapping) =>
+    mapping.sourceAccount === sourceAccount
+      ? enrichAccountMappingsWithVat([mapping], existingAccounts)[0]
+      : mapping
+  )
+}